From the [documentation][1]

&gt; A raw string is delimited by a triple quote (&quot;&quot;&quot;), contains no
&gt; escaping and can contain newlines and any other character

You would need to use a standard string with newlines

    &quot; ...\n \$eq \n ... &quot;

or you could use the literal representation 

    &quot;&quot;&quot; ... ${&#39;$&#39;}eq ... &quot;


  [1]: https://kotlinlang.org/docs/reference/basic-types.html#string-literals

Funny, but that works:

    val eq = &quot;\$eq&quot;

    print(&quot;&quot;&quot;... $eq  ...&quot;&quot;&quot;&quot;)   // just like you asked :D

Actually, if `eq` is a number (a price, or sth), then you probably want to calculate it separately, and an additional external calculation as I suggested won&#39;t hurt. 

In the case where you know ahead of time what `$`-variables you want (like when querying Mongo, as it looks like you might be doing), you can create a little helper object that defines those variables. You also get some protection against accidentally misspelling one of your operators, which is neat.

    object MongoString {
    	inline operator fun invoke(callback: MongoString.() -&gt; String) = callback()

    	val eq = &quot;\$eq&quot;
    	val lt = &quot;\$lt&quot;
    	// ... and all the other operators ...
    }

    fun test() {
    	val query = MongoString { &quot;&quot;&quot;{&quot;foo&quot;: {$lt: 10}}&quot;&quot;&quot; }
    }

I wrote simple versions for update and query strings for mongo here: https://gist.github.com/Yona-Appletree/29be816ca74a0d93cdf9e6f5e23dda15

I installed postgres using homebrew.
I would like to locate he files pg_hba.conf and postgresql.conf but I cannot find them.

I followed this :

https://askubuntu.com/questions/256534/how-do-i-find-the-path-to-pg-hba-conf-from-the-shell

and this 

http://www.kelvinwong.ca/tag/pg_hba-conf/

but I still cannot find it.

Cannot find pg_hba.conf and postgreql.conf file on OS X?

here is my use case in JavaScript:

I have two arrays of objects which have properties that match (id &amp; name).

    var result1 = [
        {id:1, name:&#39;Sandra&#39;, type:&#39;user&#39;, username:&#39;sandra&#39;},
        {id:2, name:&#39;John&#39;, type:&#39;admin&#39;, username:&#39;johnny2&#39;},
        {id:3, name:&#39;Peter&#39;, type:&#39;user&#39;, username:&#39;pete&#39;},
        {id:4, name:&#39;Bobby&#39;, type:&#39;user&#39;, username:&#39;be_bob&#39;}
    ];

    var result2 = [
        {id:2, name:&#39;John&#39;, email:&#39;johnny@example.com&#39;},
        {id:4, name:&#39;Bobby&#39;, email:&#39;bobby@example.com&#39;}
    ];

    var props = [&#39;id&#39;, &#39;name&#39;];

My goal is to have another array of objects containing only the elements which did not match. Like this:

    var result = [
        {id:1, name:&#39;Sandra&#39;},
        {id:3, name:&#39;Peter&#39;}
    ];

I know that there is a way of doing this by going from result1 compare each object with the objects of result2, then compare their keys, and if did&#39;n match, put the values in another object then push it in new array, but I wonder is there any more elegant way, like using lo-dash or underscore or something similar.

Thank you!

Comparing two arrays of objects, and exclude the elements who match values into new array in JS

If I want to use `$` sign in multiline strings, how do I escape it?
&lt;!-- language: kotlin --&gt;

    val condition = &quot;&quot;&quot; ... $eq ... &quot;&quot;&quot;

`$eq` is parsed as a reference to a variable. How to escape `$`, so that it will not be recognized as reference to variable? (Kotlin M13)

Templates escaping in Kotlin multiline strings

If I want to use <code>$</code> sign in multiline strings, how do I escape it?

<pre><code class="hljs language-ini">val condition = """ ... $eq ... """
</code></pre>
<code>$eq</code> is parsed as a reference to a variable. How to escape <code>$</code>, so that it will not be recognized as reference to variable? (Kotlin M13)

I&#39;ve very recently migrated to Python 3.5.
This code was working properly in Python 2.7:

    with open(fname, &#39;rb&#39;) as f:
        lines = [x.strip() for x in f.readlines()]

    for line in lines:
        tmp = line.strip().lower()
        if &#39;some-pattern&#39; in tmp: continue
        # ... code

After upgrading to 3.5, I&#39;m getting the:

&gt; TypeError: a bytes-like object is required, not &#39;str&#39;

The error is on the last line (the pattern search code).

I&#39;ve tried using the `.decode()` function on either side of the statement and also tried:

    if tmp.find(&#39;some-pattern&#39;) != -1: continue

\- to no avail.

I was able to resolve almost all Python&amp;nbsp;2-to-Python&amp;nbsp;3  issues quickly, but this little statement was bugging me.





TypeError: a bytes-like object is required, not &#39;str&#39; when writing to a file in Python 3

As the title states, what is the difference between these two flags? It seems they both convert the value to a string using repr()?
Also, in this line of code: 

    &quot;{0!r:20}&quot;.format(&quot;Hello&quot;)  
What does the 0 in front of the !r do?

What is the difference between !r and %r in Python?

I&#39;m trying to add some values from my database to a `[]string` in Go. Some of these are timestamps.

I get the error:

&gt; cannot use U.Created_date (type time.Time) as type string in array element

Can I convert `time.Time` to `string`?

    type UsersSession struct {
        Userid int
        Timestamp time.Time
        Created_date time.Time
    }

    type Users struct {
        Name string
        Email string
        Country string
        Created_date time.Time
        Id int
        Hash string
        IP string
    }

-

    var usersArray = [][]string{}

    rows, err := db.Query(&quot;SELECT u.id, u.hash, u.name, u.email, u.country, u.IP, u.created_date, us.timestamp, us.created_date FROM usersSession AS us LEFT JOIN users AS u ON u.id = us.userid WHERE us.timestamp + interval 30 minute &gt;= now()&quot;)

    U := Users{}
    US := UsersSession{}

    for rows.Next() {
        err = rows.Scan(&amp;U.Id, &amp;U.Hash, &amp;U.Name, &amp;U.Email, &amp;U.Country, &amp;U.IP, &amp;U.Created_date, &amp;US.Timestamp, &amp;US.Created_date)
        checkErr(err)

        userid_string := strconv.Itoa(U.Id)
        user := []string{userid_string, U.Hash, U.Name, U.Email, U.Country, U.IP, U.Created_date, US.Timestamp, US.Created_date}
        // -------------
        // ^ this is where the error occurs
        // cannot use U.Created_date (type time.Time) as type string in array element (for US.Created_date and US.Timestamp aswell)
        // -------------

        usersArray = append(usersArray, user)
        log.Print(&quot;usersArray: &quot;, usersArray)
    }


**EDIT**

I added the following. It works now, thanks.

    userCreatedDate := U.Created_date.Format(&quot;2006-01-02 15:04:05&quot;)
    userSessionCreatedDate := US.Created_date.Format(&quot;2006-01-02 15:04:05&quot;)
    userSessionTimestamp := US.Timestamp.Format(&quot;2006-01-02 15:04:05&quot;)

Convert time.Time to string

Python can multiply strings like so:

    Python 3.4.3 (default, Mar 26 2015, 22:03:40)
    [GCC 4.9.2] on linux
    Type &quot;help&quot;, &quot;copyright&quot;, &quot;credits&quot; or &quot;license&quot; for more information.
    &gt;&gt;&gt; x = &#39;my new text is this long&#39;
    &gt;&gt;&gt; y = &#39;#&#39; * len(x)
    &gt;&gt;&gt; y
    &#39;########################&#39;
    &gt;&gt;&gt;

Can Golang do the equivalent somehow?


Can Golang multiply strings like Python can?

I can convert `Vec&lt;String&gt;` to `Vec&lt;&amp;str&gt;` this way:

    let mut items = Vec::&lt;&amp;str&gt;::new();
    for item in &amp;another_items {
        items.push(item);
    }

Are there better alternatives?

How do I convert a Vec&lt;String&gt; to Vec&lt;&amp;str&gt;?

I am trying to create a parameterized class with a `lateinit` non-nullable property of the generic type:

    class Test&lt;T&gt; {
    
       private lateinit var t : T
    
       private lateinit var s : String
    
    }

The latter is allowed, but the former is not. The compiler returns the following error:

&gt; Error:(7, 11) &#39;&#39;lateinit&#39;&#39; modifier is not allowed on nullable properties

Since I didn&#39;t declare `T?`, I am confused as to why this is the case.

Why is a generic typed property nullable?

How can a method be statically imported in Kotlin? For example, in Java it&#39;s possible to do:

    ...
    import static org.mockito.Mockito.verify;
    ...
    class FoobarTest {
         ...
         @Test public void testFoo() {
              verify(mock).doSomething();
         } 
    }

How can the same be done in Kotlin without having to fully qualify the method every time with `Mockito.verify(mock).doSomething()`?



Static method imports in Kotlin

I have following fragment class written in Java using the new databinding library

    import com.example.app.databinding.FragmentDataBdinding;
    
    public class DataFragment extends Fragment {

        @Nullable
        private FragmentDataBinding mBinding;

        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            mBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_data, container, false);
            return mBinding.getRoot();
        }
    }

It compiles and runs fine.  
I tried to rewrite it in Kotlin and came up with the following:

    import com.example.app.databinding.FragmentDataBdinding

    class ProfileFragment : Fragment() {
    
        private var mBinding: FragmentDataBinding? = null

        override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
            mBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_data, container, false)
            return mBinding!!.getRoot()
        }
    }

But now step `:app:compileDebugKotlin` outputs the following:

&gt; Error:(16, 38) Unresolved reference: databinding  
&gt; Error:(37, 27) Unresolved reference: FragmentDataBinding

How can I use android-databinding library with Kotlin?

My top-level `build.gradle`:

    buildscript {
        repositories {
            jcenter()
        }
        dependencies {
            classpath &#39;com.android.tools.build:gradle:1.3.0&#39;
            classpath &#39;com.android.databinding:dataBinder:1.0-rc4&#39;
        }
    }

    allprojects {
        repositories {
            jcenter()
        }
    }

My `build.gradle` in app dir (only relevant parts):

    apply plugin: &#39;com.android.application&#39;
    apply plugin: &#39;com.android.databinding&#39;
    apply plugin: &#39;kotlin-android&#39;

    dependencies {
        compile &quot;org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version&quot;
    }

    buildscript {
        ext.kotlin_version = &#39;0.14.451&#39;
        repositories {
            mavenCentral()
        }

        dependencies {
            classpath &quot;org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version&quot;
            classpath &quot;org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version&quot;
        }
    }
    repositories {
        mavenCentral()
        maven {
            url &#39;http://oss.sonatype.org/content/repositories/snapshots&#39;
        }
    }

I&#39;m using Android Studio 1.4, Build tools version 23.0.1, Android SDK 23, SDK tools 24.4.0

Kotlin-android: unresolved reference databinding

Seems so simple, but, how do I initialize Kotlin&#39;s `MutableList` to empty `MutableList`?

I could hack it this way, but I&#39;m sure there is something easier available:

    var pusta: List&lt;Kolory&gt; = emptyList()
    var cos: MutableList&lt;Kolory&gt; = pusta.toArrayList()


How do I initialize Kotlin&#39;s MutableList to empty MutableList?

I am new in kotlin. I have found and tried to use synthetic method instead of annoying method `findViewById` in my `Activity` class, but I have found &quot;If we want to call the synthetic properties on View (useful in adapter classes), we should also import kotlinx.android.synthetic.main.view.*.&quot; But I can&#39;t figure out how it exactly works? Is there any examples?

Kotlin synthetic in Adapter or ViewHolder

The following code is wrong (see it [on ideone](http://ideone.com/vSoRsM)):

    public class Test
    {
    	public static void Main()
    	{
    	    int j = 5;
    	    (j++);      // if we remove the &quot;(&quot; and &quot;)&quot; then this compiles fine.
    	}
    }

&gt; error CS0201: Only assignment, call, increment, decrement, await, and
&gt; new object expressions can be used as a statement

1. Why does the code compile when we remove the parentheses?
2. Why does it not compile with the parentheses?
3. Why was C# designed that way?

Why was the statement (j++); forbidden?

If I&#39;m creating a component, it seems you can create a class in a lot of different ways. What is the difference between these? How do I know which one to use?

    import React, {Component} from &#39;react&#39;

    export default class Header extends Component {

    }

    export const Header = React.createClass({
    
    })

    export default React.createClass({
    
    })

I&#39;m just assuming they do different things, or is it just different syntax?

If someone could give me a quick explanation, or a link, I would really appreciate it. I don&#39;t want to start out with a new framework not knowing exactly what the difference is.

Export (default) class in ReactJS

Coming from Python, I&#39;m not used to see code lines longer than 80 columns.
So when I encounter this:

    err := database.QueryRow(&quot;select * from users where user_id=?&quot;, id).Scan(&amp;ReadUser.ID, &amp;ReadUser.Name, &amp;ReadUser.First, &amp;ReadUser.Last, &amp;ReadUser.Email)

I tried to break it to 

    err := database.QueryRow(&quot;select * from users where user_id=?&quot;, id) \
    	.Scan(&amp;ReadUser.ID, &amp;ReadUser.Name, &amp;ReadUser.First, &amp;ReadUser.Last, &amp;ReadUser.Email)

But I get 

     syntax error: unexpected \

I also tried just breaking the line with hitting enter and put a semicolon at the end:

    err := database.QueryRow(&quot;select * from users where user_id=?&quot;, id) 
    .Scan(&amp;ReadUser.ID, &amp;ReadUser.Name, &amp;ReadUser.First, &amp;ReadUser.Last, &amp;ReadUser.Email);

But the I again get:

    syntax error: unexpected .

So I&#39;m wondering what&#39;s the golangic way to do so?



How to break a long line of code in Golang?

Instead of `2*i`, I carelessly wrote `2i`:

    int foo(int i)
    {
        2i;
    	return 2i;
    }

I expected the compiler to catch the error. But it did not. So is `2i` a valid statement in C? If so what does it do? Puzzled!

I compiled using gcc version 5.3.0 and here is the assembly output:

    	.file	&quot;strange.c&quot;
    	.text
    	.globl	foo
    	.type	foo, @function
    foo:
    .LFB0:
    	.cfi_startproc
    	pushq	%rbp
    	.cfi_def_cfa_offset 16
    	.cfi_offset 6, -16
    	movq	%rsp, %rbp
    	.cfi_def_cfa_register 6
    	movl	%edi, -4(%rbp)
    	nop
    	popq	%rbp
    	.cfi_def_cfa 7, 8
    	ret
    	.cfi_endproc
    .LFE0:
    	.size	foo, .-foo
    	.ident	&quot;GCC: (GNU) 5.3.0&quot;
    	.section	.note.GNU-stack,&quot;&quot;,@progbits



Why does the statement &quot;2i;&quot; NOT cause a compiler error?

The following code compiles without problems:

    int main() {
        printf(&quot;Hi&quot; &quot;Bye&quot;);
    }

However, this does not compile:

    int main() {
        int test = 0;
        printf(&quot;Hi&quot; (test ? &quot;Bye&quot; : &quot;Goodbye&quot;));
    }

What is the reason for that?

Content Type	Original Author	Original Content on Stackoverflow
Question	ntoskrnl	View Question on Stackoverflow
Solution 1 - String	Jeremy Lyman	View Answer on Stackoverflow
Solution 2 - String	voddan	View Answer on Stackoverflow
Solution 3 - String	Yona Appletree	View Answer on Stackoverflow

Templates escaping in Kotlin multiline strings

String Problem Overview

String Solutions

Solution 1 - String

Solution 2 - String

Solution 3 - String

Comparing two arrays of objects, and exclude the elements who match values into new array in JS

Cannot find pg_hba.conf and postgreql.conf file on OS X?

Attributions