I&#39;m looking for a `string.contains` or `string.indexof` method in Python.

I want to do:

    if not somestring.contains(&quot;blah&quot;):
       continue


Does Python have a string &#39;contains&#39; substring method?

Is there a way to make the following return true?

    string title = &quot;ASTRINGTOTEST&quot;;
    title.Contains(&quot;string&quot;);

There doesn&#39;t seem to be an overload that allows me to set the case sensitivity. Currently I UPPERCASE them both, but that&#39;s just silly (by which I am referring to the [i18n][1] issues that come with up- and down casing).

**UPDATE**  

This question is ancient and since then I have realized I asked for a simple answer for a really vast and difficult topic if you care to investigate it fully.  

For most cases, in mono-lingual, English code bases [this][2] answer will suffice. I&#39;m suspecting because most people coming here fall in this category this is the most popular answer. 
 
[This][3] answer however brings up the inherent problem that we can&#39;t compare text case insensitive until we know both texts are the same culture and we know  what that culture is. This is maybe a less popular answer, but I think it is more correct and that&#39;s why I marked it as such.

  [1]: http://en.wikipedia.org/wiki/Internationalization_and_localization
  [2]: https://stackoverflow.com/a/444818/11333
  [3]: https://stackoverflow.com/a/15464440/11333

Case insensitive &#39;Contains(string)&#39;

Consider:

    $a = &#39;How are you?&#39;;

    if ($a contains &#39;are&#39;)
        echo &#39;true&#39;;

Suppose I have the code above, what is the correct way to write the statement `if ($a contains &#39;are&#39;)`?


How do I check if a string contains a specific word?

I need to determine if a value exists in an array.

I am using the following function:

    Array.prototype.contains = function(obj) {
        var i = this.length;
        while (i--) {
            if (this[i] == obj) {
                return true;
            }
        }
        return false;
    }

The above function always returns false.

The array values and the function call is as below:

    arrValues = [&quot;Sam&quot;,&quot;Great&quot;, &quot;Sample&quot;, &quot;High&quot;]
    alert(arrValues.contains(&quot;Sam&quot;));



Determine whether an array contains a value

I have a shopping cart that displays product options in a dropdown menu and if they select &quot;yes&quot;, I want to make some other fields on the page visible. 

The problem is that the shopping cart also includes the price modifier in the text, which can be different for each product. The following code works:

    $(document).ready(function() {
        $(&#39;select[id=&quot;Engraving&quot;]&#39;).change(function() {
            var str = $(&#39;select[id=&quot;Engraving&quot;] option:selected&#39;).text();
            if (str == &quot;Yes (+ $6.95)&quot;) {
                $(&#39;.engraving&#39;).show();
            } else {
                $(&#39;.engraving&#39;).hide();
            }
        });
    });

However I would rather use something like this, which doesn&#39;t work:

    $(document).ready(function() {
        $(&#39;select[id=&quot;Engraving&quot;]&#39;).change(function() {
            var str = $(&#39;select[id=&quot;Engraving&quot;] option:selected&#39;).text();
            if (str *= &quot;Yes&quot;) {
                $(&#39;.engraving&#39;).show();
            } else {
                $(&#39;.engraving&#39;).hide();
            }
        });
    });

I only want to perform the action if the selected option contains the word &quot;Yes&quot;, and would ignore the price modifier.

How do I check if string contains substring?

I see people are using `any` to gather another list to see if an item exists in a list, but is there a quick way to just do something like this?

    if list.contains(myItem):
        # do something

Is there a short contains function for lists?

How do you check that an element is in a set?

Is there a simpler equivalent of the following code:

    myset.find(x) != myset.end()


How to check that an element is in a std::set?

If I&#39;ve got an array of strings, can I check to see if a string is in the array without doing a `for` loop?  Specifically, I&#39;m looking for a way to do it within an `if` statement, so something like this:

    if [check that item is in array]:

Check if item is in an array / list

Which one of the following queries is faster (LIKE vs CONTAINS)?

    SELECT * FROM table WHERE Column LIKE &#39;%test%&#39;;

or

    SELECT * FROM table WHERE Contains(Column, &quot;test&quot;);


LIKE vs CONTAINS on SQL Server

I want to check whether a `List` contains an object that has a field with a certain value. Now, I could use a loop to go through and check, but I was curious if there was anything more code efficient. 

Something like;

    if(list.contains(new Object().setName(&quot;John&quot;))){
        //Do some stuff
    }

I know the above code doesn&#39;t do anything, it&#39;s just to demonstrate roughly what I am trying to achieve.

Also, just to clarify, the reason I don&#39;t want to use a simple loop is because this code will currently go inside a loop that is inside a loop which is inside a loop. For readability I don&#39;t want to keep adding loops to these loops. So I wondered if there were any simple(ish) alternatives.

Java List.contains(Object with field value equal to x)

Pretty straight forward. In javascript, I need to check if a string contains any substrings held in an array.

How to check if a string contains text from an array of substrings in JavaScript?

I&#39;ve done some searching and can&#39;t figure out how to filter a dataframe by 

    df[&quot;col&quot;].str.contains(word)

however I&#39;m wondering if there is a way to do the reverse: filter a dataframe by that set&#39;s compliment. eg: to the effect of 

    !(df[&quot;col&quot;].str.contains(word))

Can this be done through a `DataFrame` method?

Search for &quot;does-not-contain&quot; on a DataFrame in pandas

How can I check if a value that is written in scanner exists in an `ArrayList`?

    List&lt;CurrentAccount&gt; lista = new ArrayList&lt;CurrentAccount&gt;();

    CurrentAccount conta1 = new CurrentAccount(&quot;Alberto Carlos&quot;, 1052);
    CurrentAccount conta2 = new CurrentAccount(&quot;Pedro Fonseca&quot;, 30);
    CurrentAccount conta3 = new CurrentAccount(&quot;Ricardo Vitor&quot;, 1534);
    CurrentAccount conta4 = new CurrentAccount(&quot;Jo&#227;o Lopes&quot;, 3135);
    
    lista.add(conta1);
    lista.add(conta2);
    lista.add(conta3);
    lista.add(conta4);
    
    Collections.sort(lista);
    
    System.out.printf(&quot;Bank Accounts:&quot; + &quot;%n&quot;);
    Iterator&lt;CurrentAccount&gt; itr = lista.iterator();
    while (itr.hasNext()) {
        CurrentAccount element = itr.next();
        System.out.printf(element + &quot; &quot; + &quot;%n&quot;);
    }
    System.out.println();



Check if a value exists in ArrayList

Is it possible to determine if a String `str1=&quot;ABCDEFGHIJKLMNOP&quot;` contains a string pattern `strptrn=&quot;gHi&quot;`? I wanted to know if that&#39;s possible when the characters are case insensitive. If so, how?

String contains - ignore case

While searching for an answer to this question, I&#39;ve run into similar ones utilizing LINQ but I haven&#39;t been able to fully understand them (and thus, implement them), as I&#39;m not familiarized with it. What I would like to, basically, is this:

1. Check if any element of a list contains a specific string.
2. If it does, get that element.

I honestly don&#39;t know how I would go about doing that. What I can come up with is this (not working, of course):

    if (myList.Contains(myString))
        string element = myList.ElementAt(myList.IndexOf(myString));

I know WHY it does not work:

- `myList.Contains()` does not return `true`, since it will check for if a whole element of the list matches the string I specified.
- `myList.IndexOf()` will not find an occurrence, since, as it is the case again, it will check for an element matching the string.

Still, I have no clue how to solve this problem, but I figure I&#39;ll have to use LINQ as suggested in similar questions to mine. That being said, if that&#39;s the case here, I&#39;d like for the answerer to explain to me the use of LINQ in their example (as I said, I haven&#39;t bothered with it in my time with C#). Thank you in advance guys (and gals?).

EDIT: I have come up with a solution; just loop through the list, check if current element contains the string and then set a string equal to the current element. I&#39;m wondering, though, is there a more efficient way than this?

    string myString = &quot;bla&quot;;
    string element = &quot;&quot;;

    for (int i = 0; i &lt; myList.Count; i++)
    {
        if (myList[i].Contains(myString))
            element = myList[i];
    }



Check if list contains element that contains a string and get that element

Is there a method for checking if a table contains a value ? I have my own (naive) function, but I was wondering if something &quot;official&quot; exists for that ? Or something more efficient...

    function table.contains(table, element)
      for _, value in pairs(table) do
        if value == element then
          return true
        end
      end
      return false
    end

By the way, the main reason I&#39;m using this functions is to use tables as sets, ie with no duplicate elements. Is there something else I could use ?

How to check if a table contains an element in Lua?

I want to check if a String s, contains &quot;a&quot; or &quot;b&quot; or &quot;c&quot;, in C#.
I am looking for a nicer solution than using
 
    if (s.contains(&quot;a&quot;)||s.contains(&quot;b&quot;)||s.contains(&quot;c&quot;))


How to check if a String contains any of some strings

    public class PricePublicModel
    {
        public PricePublicModel() { }
    
        public int PriceGroupID { get; set; }
        public double Size { get; set; }
        public double Size2 { get; set; }
        public int[] PrintType { get; set; }
        public double[] Price { get; set; }
    }

    List&lt;PricePublicModel&gt; pricePublicList = new List&lt;PricePublicModel&gt;();



How to check if element of `pricePublicList` contains certain value. To be more precise, I want to check if there exists `pricePublicModel.Size == 200`? Also, if this element exists, how to know which one it is?


EDIT If Dictionary is more suitable for this then I could use Dictionary, but I would need to know how :) 


how to check if List&lt;T&gt; element contains an item with a Particular Property Value

I need to check whether a string contains another string or not?

    var str1 = &quot;ABCDEFGHIJKLMNOP&quot;;
    var str2 = &quot;DEFG&quot;;

Which function do I use to find out if str1 contains str2?

JQuery string contains check

I&#39;m trying to use the `.Contains()` function on a list of custom objects

This is the list:

    List&lt;CartProduct&gt; CartProducts = new List&lt;CartProduct&gt;();

And the `CartProduct`:

    public class CartProduct
    {
        public Int32 ID;
        public String Name;
        public Int32 Number;
        public Decimal CurrentPrice;
        /// &lt;summary&gt;
        /// 
        /// &lt;/summary&gt;
        /// &lt;param name=&quot;ID&quot;&gt;The ID of the product&lt;/param&gt;
        /// &lt;param name=&quot;Name&quot;&gt;The name of the product&lt;/param&gt;
        /// &lt;param name=&quot;Number&quot;&gt;The total number of that product&lt;/param&gt;
        /// &lt;param name=&quot;CurrentPrice&quot;&gt;The currentprice for the product (1 piece)&lt;/param&gt;
        public CartProduct(Int32 ID, String Name, Int32 Number, Decimal CurrentPrice)
        {
            this.ID = ID;
            this.Name = Name;
            this.Number = Number;
            this.CurrentPrice = CurrentPrice;
        }
        public String ToString()
        {
            return Name;
        }
    }

So i try to find a similar cartproduct within the list:

    if (CartProducts.Contains(p))

But it ignores similar cartproducts and i don&#39;t seem to know what it checks on - the ID? or it all?

Thanks in advance! :)

.Contains() on a list of custom class objects

Basically my mate has been saying that I could make my code shorter by using a different way of checking if an int array contains an int, although he won&#39;t tell me what it is :P.

Current: 

    public boolean contains(final int[] array, final int key) {
        for (final int i : array) {
            if (i == key) {
                return true;
            }
        }
        return false;
    }

Have also tried this, although it always returns false for some reason.

    public boolean contains(final int[] array, final int key) {
        return Arrays.asList(array).contains(key);
    }

Could anyone help me out?

Thank you.

Java, Simplified check if int array contains int

I got one big question.

I got a linq query to put it simply looks like this:

    from xx in table
    where xx.uid.ToString().Contains(string[])
    select xx

The values of the `string[]` array would be numbers like (1,45,20,10,etc...)

the Default for `.Contains` is `.Contains(string)`.

I need it to do this instead:  `.Contains(string[])`...

**EDIT :** One user suggested writing an extension class for `string[]`.  I would like to learn how, but any one willing to point me in the right direction?

**EDIT :** The uid would also be a number. That&#39;s why it is converted to a string.

Help anyone?

How do I use LINQ Contains(string[]) instead of Contains(string)

I&#39;m trying to use &quot;contains&quot; case insensitively. I tried using the solution at the following stackoverflow question, but it didn&#39;t work:

https://stackoverflow.com/questions/187537/is-there-a-case-insensitive-jquery-contains-selector/187557#187557

*For convenience, the solution is copied here:*

    jQuery.extend(
            jQuery.expr[&#39;:&#39;], { 
                    Contains : &quot;jQuery(a).text().toUpperCase().indexOf(m[3].toUpperCase())&gt;=0&quot; 
    });


*Here is the error:*

    Error: q is not a function
    Source File: /js/jquery-1.4.js?ver=1.4
    Line: 81

*Here&#39;s where I&#39;m using it:*

      $(&#39;input.preset&#39;).keyup(function() {
        $(this).next().find(&quot;li&quot;).removeClass(&quot;bold&quot;);
        var theMatch = $(this).val();
        if (theMatch.length &gt; 1){
          theMatch = &quot;li:Contains(&#39;&quot; + theMatch + &quot;&#39;)&quot;;
          $(this).next().find(theMatch).addClass(&quot;bold&quot;);
        }
      });

My use of the original case sensitive &quot;contains&quot; in the same scenario works without any errors. Does anyone have any ideas? I&#39;d appreciate it.


How do I make jQuery Contains case insensitive, including jQuery 1.8+?

Like the title says, I want to replace a specific part of the text in a div.

The structure looks like this:

    &lt;div class=&quot;text_div&quot;&gt;
        This div contains some text.
    &lt;/div&gt;

And I want to replace only &quot;contains&quot; with &quot;hello everyone&quot;, for example.
I can&#39;t find a solution for this.

jQuery if div contains this text, replace that part of the text

I have some XML that is structured like this:

    &lt;whatson&gt;
      &lt;productions&gt;    
        &lt;production&gt;
          &lt;category&gt;Film&lt;/category&gt;
        &lt;/production&gt;
        &lt;production&gt;
          &lt;category&gt;Business&lt;/category&gt;
        &lt;/production&gt;
        &lt;production&gt;
          &lt;category&gt;Business training&lt;/category&gt;
        &lt;/production&gt;
      &lt;/productions&gt;
    &lt;/whatson&gt;

And I need to select every production with a category that doesn&#39;t contain &quot;Business&quot; (so just the first production in this example).

Is this possible with XPath? I tried working along these lines but got nowhere:

    //production[not(contains(category,&#39;business&#39;))]

How to use not contains() in XPath?

Is there an xpath way to find a node that has a given attribute whose value contains a given string?

For example I have an xml document and want to find a node where the `address` attribute contains the string `Downing`, so that I could find the following node:

    &lt;person name=&quot;blair&quot; address=&quot;10 Downing St. London&quot;/&gt;

xpath: find a node that has a given attribute whose value contains a string

UPDATE 3: According to [this announcement][1], this has been addressed by the EF team in EF6 alpha 2.

UPDATE 2: I&#39;ve created a suggestion to fix this problem. To vote for it, [go here][2].

Consider a SQL database with one very simple table.

    CREATE TABLE Main (Id INT PRIMARY KEY)

I populate the table with 10,000 records.

    WITH Numbers AS
    (
      SELECT 1 AS Id
      UNION ALL
      SELECT Id + 1 AS Id FROM Numbers WHERE Id &lt;= 10000
    )
    INSERT Main (Id)
    SELECT Id FROM Numbers
    OPTION (MAXRECURSION 0)

I build an EF model for the table and run the following query in LINQPad (I am using &quot;C# Statements&quot; mode so LINQPad doesn&#39;t create a dump automatically).

    var rows = 
      Main
      .ToArray();

Execution time is ~0.07 seconds. Now I add the Contains operator and re-run the query.

    var ids = Main.Select(a =&gt; a.Id).ToArray();
    var rows = 
      Main
      .Where (a =&gt; ids.Contains(a.Id))
      .ToArray();

Execution time for this case is **20.14 seconds** (288 times slower)!

At first I suspected that the T-SQL emitted for the query was taking longer to execute, so I tried cutting and pasting it from LINQPad&#39;s SQL pane into SQL Server Management Studio.

    SET NOCOUNT ON
    SET STATISTICS TIME ON
    SELECT 
    [Extent1].[Id] AS [Id]
    FROM [dbo].[Primary] AS [Extent1]
    WHERE [Extent1].[Id] IN (1,2,3,4,5,6,7,8,...

And the result was

    SQL Server Execution Times:
      CPU time = 0 ms,  elapsed time = 88 ms.

Next I suspected LINQPad was causing the problem, but performance is the same whether I run it in LINQPad or in a console application.

So, it appears that the problem is somewhere within Entity Framework.

Am I doing something wrong here? This is a time-critical part of my code, so is there something I can do to speed up performance?

I am using Entity Framework 4.1 and Sql Server 2008 R2.

UPDATE 1:

In the discussion below there were some questions about whether the delay occurred while EF was building the initial query or while it was parsing the data it received back. To test this I ran the following code,

    var ids = Main.Select(a =&gt; a.Id).ToArray();
    var rows = 
      (ObjectQuery&lt;MainRow&gt;)
      Main
      .Where (a =&gt; ids.Contains(a.Id));
    var sql = rows.ToTraceString();

which forces EF to generate the query without executing it against the database. The result was that this code required ~20 secords to run, so it appears that almost all of the time is taken in building the initial query.

CompiledQuery to the rescue then? Not so fast ... CompiledQuery requires the parameters passed into the query to be fundamental types (int, string, float, and so on). It won&#39;t accept arrays or IEnumerable&lt;int&gt;, so I can&#39;t use it for a list of Ids.


  [1]: http://blogs.msdn.com/b/adonet/archive/2012/12/10/ef6-alpha-2-available-on-nuget.aspx
  [2]: http://data.uservoice.com/forums/72025-ado-net-entity-framework-ef-feature-suggestions/suggestions/2598644-improve-the-performance-of-the-contains-operator

Why does the Contains() operator degrade Entity Framework&#39;s performance so dramatically?

I would like to match the following text `sometext12345_text` using the below regex. 

I&#39;m using this in one of my selenium tests.

    String expr = &quot;//*[contains(@id, &#39;sometext[0-9]+_text&#39;)]&quot;;
    driver.findElement(By.xpath(expr));

It doesn&#39;t seem to work though. Can somebody help?

How to use regex in XPath &quot;contains&quot; function

Assuming i have:

    &lt;li id=&quot;1&quot;&gt;Mary&lt;/li&gt;
    &lt;li id=&quot;2&quot;&gt;John, Mary, Dave&lt;/li&gt;
    &lt;li id=&quot;3&quot;&gt;John, Dave, Mary&lt;/li&gt;
    &lt;li id=&quot;4&quot;&gt;John&lt;/li&gt;

If i need to find all &amp;lt;li&amp;gt; Elements which contain &quot;John&quot; and &quot;Mary&quot;, how would i construct the jQuery?

A search for a single string seems easy:

    $(&#39;li:contains(&quot;John&quot;)&#39;).text()

I am looking for something like the following pseudo code:

    $(&#39;li:contains(&quot;John&quot;)&#39; &amp;&amp; &#39;li:contains(&quot;Mary&quot;)&#39;).text()

Thanks!





jQuery :contains selector to search for multiple strings

Basically I have about 1,000,000 strings, for each request I have to check if a String belongs to the list or not.

I&#39;m worried about the performance, so what&#39;s the best method? `ArrayList`? Hash?

Fastest way to check if a List&lt;String&gt; contains a unique String

I thought it was `CONTAINS`, but that&#39;s not working for me. 

I&#39;m looking to do this:

    IF CONTAINS(@stringVar, &#39;thisstring&#39;)
       ...

I have to run one `select` or another, depending on whether that variable contains a string and I can&#39;t figure out how to get it to work. All the examples I&#39;m seeing are using columns in the contains. 

Thanks in advance.

How can I tell if a VARCHAR variable contains a substring?

I have an enum

    enum myEnum2 { ab, st, top, under, below}

I would like to write a function to test if a given value is included in myEnum

something like that:

    private bool EnumContainValue(Enum myEnum, string myValue)
    {
         return Enum.GetValues(typeof(myEnum))
                    .ToString().ToUpper().Contains(myValue.ToUpper()); 
    }

But it doesn&#39;t work because myEnum parameter is not recognized.

C# enum contains value

I have two strings in scala and I want to find out, if the bigger string (`needle`) contains a smaller string (`haystack`).

What I found is doing it with regexps and matches like this ([from this question][1]):

`needle.r.pattern.matcher(haystack).matches`

which is (1) grossly overcomplicated for such a simple problem, but more importantly, (2) doesn&#39;t work for me, because

`&quot;needle&quot;.r.pattern.matcher(&quot;Finding needle in haystack&quot;).matches`

returns

`Boolean = false`

  [1]: https://stackoverflow.com/questions/3021813/how-to-check-whether-a-string-fully-matches-a-regex-in-scala

What is the idiomatic scala way of finding, if a given string contains a given substring?

There is probably a simple one-liner that I am just not finding here, but this is my question:

How do I check if an ArrayList contains all of the objects in another ArrayList?  I am looking (if it exists) for something along the lines of:

    //INCORRECT EXAMPLE:
    if(one.contains(two))
    {
        return true;
    }
    else
    {
        return false;
    }

For example:

    ArrayList one = {1, 2, 3, 4, 5}
    
    ArrayList two = {1, 2, 3} --&gt; True
    ArrayList two = {} --&gt; True
    ArrayList two = {1, 2, 3, 4, 5} --&gt; True
    ArrayList two = {1, 5, 2} --&gt; True
    ArrayList two = {1, 7, 4} --&gt; False
    ArrayList two = {0, 1, 3} --&gt; False
    ArrayList two = {4, 5, 6} --&gt; False
    ArrayList two = {7, 8, 9} --&gt; False

Check if an ArrayList contains every element from another ArrayList (or Collection)

Is there a shorter way of writing something like this:
&lt;!-- language-all: lang-cs --&gt;

    if(x==1 || x==2 || x==3) // do something

What I&#39;m looking for is something like this:

    if(x.in((1,2,3)) // do something

Check if a variable is in an ad-hoc list of values

I have a two dimensional (or more) pandas DataFrame like this:

    &gt;&gt;&gt; import pandas as pd
    &gt;&gt;&gt; df = pd.DataFrame([[0,1],[2,3],[4,5]], columns=[&#39;A&#39;, &#39;B&#39;])
    &gt;&gt;&gt; df
       A  B
    0  0  1
    1  2  3
    2  4  5

Now suppose I have a numpy array like `np.array([2,3])` and want to check if there is any row in `df` that matches with the contents of my array. Here the answer should obviously true but eg. `np.array([1,2])` should return false as there is no row with both 1 in column A and 2 in column B.

Sure this is easy but don&#39;t see it right now.

Pandas: Check if row exists with certain values

&lt;p&gt;I know that the compiler sometimes provides a default copy constructor if you don&#39;t implement yourself. I am confused about what exactly this constructor does. If I have a class that contains other objects, none of which have a declared copy constructor, what will the behavior be? For example, a class like this:&lt;/p&gt;
    class Foo {
      Bar bar;
    };

    class Bar {
      int i;
      Baz baz;
    };

    class Baz {
      int j;
    };
&lt;p&gt;Now if I do this:&lt;/p&gt;
    Foo f1;
    Foo f2(f1);
&lt;p&gt;What will the default copy constructor do? Will the compiler-generated copy constructor in &lt;code&gt;Foo&lt;/code&gt; call the compiler-generated constructor in &lt;code&gt;Bar&lt;/code&gt; to copy over &lt;code&gt;bar&lt;/code&gt;, which will then call the compiler-generated copy constructor in &lt;code&gt;Baz&lt;/code&gt;?

C++ implicit copy constructor for a class that contains other objects

With linq I have to check if a value of a row is present in an array.  
The equivalent of the sql query:

    WHERE ID IN (2,3,4,5)

How can I do it?

What is the linq equivalent to the SQL IN operator

I&#39;m doing an C# app where I use 

    if ((message.Contains(&quot;test&quot;)))
    {
       Console.WriteLine(&quot;yes&quot;);
    } else if ((message.Contains(&quot;test2&quot;))) {
       Console.WriteLine(&quot;yes for test2&quot;);
    }

There would be any way to change to `switch()` the `if()` statements?


Use string.Contains() with switch()

Basically, how do I make it so I can do something similar to: `CurrentCollection.Contains(...)`, except by comparing if the item&#39;s property is already in the collection?

    public class Foo
    {
        public Int32 bar;
    }


    ICollection&lt;Foo&gt; CurrentCollection;
    ICollection&lt;Foo&gt; DownloadedItems;

    //LINQ: Add any downloaded items where the bar Foo.bar is not already in the collection?

Add items to a collection if the collection does NOT already contain it by comparing a property of the items?

I&#39;ve got a list of elements, say, integers and I want to check if my variable (another integer) is one of the elements from the list. In python I&#39;d do:

    my_list = [1,2,3,4] # elements
    my_var = 3 # my variable
    my_var in my_list # returns boolean

How to do that in C++? I thought of using `std::list`, but I can find no `find` method in it. I can see such method in `std::set` structure.

More deeply, the problem is that my program is given some unique ids (a list, a set, whatever) and I iterate over a long list of input data (ids) and check if they are included in the list (boolean value returned for each iteration step). And I&#39;m not sure how should I do that in C++.

Check if element is in the list (contains)

I have a strongly typed list of custom objects, `MyObject`, which has a property `Id`, along with some other properties.

Let&#39;s say that the `Id` of a `MyObject` defines it as unique and I want to check if my collection doesn&#39;t already have a `MyObject` object that has an `Id` of 1 before I add my new `MyObject` to the collection.

I want to use `if(!List&lt;MyObject&gt;.Contains(myObj))`, but how do I enforce the fact that only one or two properties of `MyObject` define it as unique?

I can use `IComparable`? Or do I only have to override an `Equals` method? If so, I&#39;d need to inherit something first, is that right?

What does Collection.Contains() use to check for existing objects?

In Java we have `HashSet&lt;Integer&gt;`, I need similar structure in Python to use contains like below:

    A = [1, 2, 3]
    S = set()
    S.add(2)
    for x in A:
        if S.contains(x):
            print &quot;Example&quot;

Could you please help?

Contains of HashSet&lt;Integer&gt; in Python

Declaration:

    let listArray = [&quot;kashif&quot;]
    let word = &quot;kashif&quot;
then this 

    contains(listArray, word) 

Returns true but if declaration is:

    let word = &quot;Kashif&quot;

then it returns false because comparison is case sensitive. 

How to make this comparison case insensitive?  

Check if a string exists in an array case insensitively

I have an `if` statement:

    if (inventory.contains(&quot;bread&quot;))

But now I want to check

* if `inventory` contains &quot;bread&quot;
* but does not contain &quot;water&quot;.

How can I do this?

Opposite of .contains (does not contain)

I have an R string, with the format

    s = `&quot;[some letters and numbers]_[a number]_[more numbers, letters, punctuation, etc, anything]&quot;`

I simply want a way of checking if `s` contains `&quot;_2&quot;` in the first position. In other words, after the first `_` symbol, is the single number a &quot;2&quot;? How do I do this in R?

I&#39;m assuming I need some complicated regex expresion?

Examples:

    39820432_2_349802j_32hfh = TRUE

`43lda821_9_428fj_2f = FALSE` (notice there is a `_2` there, but not in the right spot)

R - test if first occurrence of string1 is followed by string2

I am trying to check if a specific item (value of a property) exists in a array of objects, but could not find out any solution. Please let me know, what i am missing here.

            class Name {
                var id : Int
                var name : String
                init(id:Int, name:String){
                    self.id = id
                    self.name = name
                }
            }
            
            var objarray = [Name]()
            objarray.append(Name(id: 1, name: &quot;Nuibb&quot;))
            objarray.append(Name(id: 2, name: &quot;Smith&quot;))
            objarray.append(Name(id: 3, name: &quot;Pollock&quot;))
            objarray.append(Name(id: 4, name: &quot;James&quot;))
            objarray.append(Name(id: 5, name: &quot;Farni&quot;))
            objarray.append(Name(id: 6, name: &quot;Kuni&quot;))
            
            if contains(objarray[&quot;id&quot;], 1) {
                println(&quot;1 exists in the array&quot;)
            }else{
                println(&quot;1 does not exists in the array&quot;)
            }

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