As per the [documentation][1], these are just synonyms.  `size()` is there to be consistent with other STL containers (like `vector`, `map`, *etc.*) and `length()` is to be consistent with most peoples&#39; intuitive notion of character strings.  People usually talk about a word, sentence or paragraph&#39;s *length*, not its size, so `length()` is there to make things more readable.


  [1]: http://en.cppreference.com/w/cpp/string/basic_string

Ruby&#39;s just the same, btw, offering both `#length` _and_ `#size` as synonyms for the number of items in arrays and hashes (C++ only does it for strings).

Minimalists and people who believe &quot;there ought to be one, and ideally only one, obvious way to do it&quot; (as the Zen of Python recites) will, I guess, mostly agree with your doubts, @Naveen, while fans of Perl&#39;s &quot;There&#39;s more than one way to do it&quot; (or SQL&#39;s syntax with a bazillion optional &quot;noise words&quot; giving umpteen identically equivalent syntactic forms to express one concept) will no doubt be complaining that Ruby, and especially C++, just don&#39;t go far enough in offering such synonymical redundancy;-).

When using coding practice tools(LeetCode) it seems that size() is quicker than length() (although basically negligible)

length of string ==how many bits that string having,
  size==size of those bits,
In strings both are same if the editor allocates size of character is 1 byte

How do I pass the command line arguments to an alias? Here is a sample:

&lt;pre&gt;
alias mkcd=&#39;mkdir $1; cd $1;&#39;
&lt;/pre&gt;

But in this case the $xx is getting translated at the alias creating time and not at  runtime. I have, however, created a workaround using a shell function (after googling a little) like below:  
&lt;pre&gt;
function mkcd(){
  mkdir $1
  cd $1
}
&lt;/pre&gt;

Just wanted to know if there is a way to make aliases that accept CL parameters.  
BTW - I use &#39;bash&#39; as my default shell.


How to pass command line arguments to a shell alias?

How to set radio option checked onload with jQuery? 

Need to check if no default is set and then set a default

how to set radio option checked onload with jQuery

I was reading the answers for this [question][1] and found that there is actually a method called `length()` for `std::string` (I always used `size()`). Is there any specific reason for having this method in `std::string` class? I read both MSDN and CppRefernce, and they seem to indicate that there is no difference between `size()` and `length()`. If that is so, isn&#39;t it making more confusing for the user of the class?


  [1]: https://stackoverflow.com/questions/905355/c-string-length

std::string length() and size() member functions

<p>I was reading the answers for this <a href="https://stackoverflow.com/questions/905355/c-string-length" target="_blank" rel="noopener noreferrer">question</a> and found that there is actually a method called <code>length()</code> for <code>std::string</code> (I always used <code>size()</code>). Is there any specific reason for having this method in <code>std::string</code> class? I read both MSDN and CppRefernce, and they seem to indicate that there is no difference between <code>size()</code> and <code>length()</code>. If that is so, isn't it making more confusing for the user of the class?</p>


I guess this is a simple question. I need to do something like this:

    std::set&lt;int&gt; s1, s2;
    s1 = getAnExcitingSet();
    std::transform(s1.begin(), s1.end(), std::back_inserter(s2), ExcitingUnaryFunctor());

Of course, `std::back_inserter` doesn&#39;t work since there&#39;s no `push_back`.
`std::inserter` also needs an iterator? I haven&#39;t used `std::inserter` so I&#39;m not sure what to do.

Does anyone have an idea?

&lt;hr&gt;
Of course, my other option is to use a vector for `s2`, and then just sort it later. Maybe that&#39;s better?

std::back_inserter for a std::set?

I am looking for a way to track memory allocations in a C++ program. I am _not_ interested in memory leaks, which seem to be what most tools are trying to find, but rather creating a memory usage profile for the application. Ideal output would be either a big list of function names plus number of maximum allocated bytes over time or better yet, a graphical representation of the heap over time. Horizontal axis is time, vertical axis heap space. Every function would get it&#39;s own color and draw lines according to allocated heap bytes. Bonus points for identifying allocated object types as well.

The idea is to find memory bottlenecks/to visualize what functions/threads consume the most memory and should be targetted for further optimization.

I have briefly looked at Purify, BoundsChecker and AQTime but they don&#39;t seem to be what I&#39;m after. Valgrind looks suitable, however, I&#39;m on Windows. [Memtrack](http://www.almostinfinite.com/memtrack.html) looks promising, but requires significant changes to the source code.

My google skills must have failed me, cause it doesn&#39;t seem to be such an uncommon request? All the needed information to create a tool like that should be readily available from the program&#39;s debug symbols plus runtime API calls - no?

track C++ memory allocations

I&#39;m a web-game developer and I got a problem with random numbers. Let&#39;s say that a player has 20% chance to get a critical hit with his sword. That means, 1 out of 5 hits should be critical. The problem is I got very bad real life results &amp;mdash; sometimes players get 3 crits in 5 hits, sometimes none in 15 hits. Battles are rather short (3-10 hits) so it&#39;s important to get good random distribution.

Currently I use PHP `mt_rand()`, but we are just moving our code to C++, so I want to solve this problem in our game&#39;s new engine.

I don&#39;t know if the solution is some uniform random generator, or maybe to remember previous random states to force proper distribution.


Need for predictable random generator

Is there is a difference between `size_t` and `container::size_type`?

What I understand is `size_t` is more generic and can be used for any `size_type`s.

But is `container::size_type` optimized for specific kinds of containers?

&#39;size_t&#39; vs &#39;container::size_type&#39;

How can I generate SHA1 or SHA2 hashes using the [OpenSSL](https://openssl.org) libarary?

I searched google and could not find any function or example code.

Generate SHA hash in C++ using OpenSSL library

original string is `&quot;a,d,k&quot;`
I want to remove all `,` and make it to `&quot;adk&quot;`. 

I tried code below but it doesn&#39;t work.

```
&quot;a,d,k&quot;.replace(/,/,&quot;&quot;)
```


how to remove &quot;,&quot; from a string in javascript

I could write my own algorithm to do it, but I feel there should be the equivalent to [ruby&#39;s humanize][1] in C#. 

I googled it but only found ways to humanize dates.

Examples:

 - A way to turn &quot;Lorem Lipsum Et&quot; into &quot;Lorem lipsum et&quot; 
 - A way to turn &quot;Lorem lipsum et&quot; into &quot;Lorem Lipsum Et&quot;

  [1]: http://api.rubyonrails.org/classes/ActiveSupport/CoreExtensions/String/Inflections.html#M001339


How to capitalize the first character of each word, or the first character of a whole string, with C#?

What&#39;s the easiest way to do a case-insensitive string replacement in Python?

Case insensitive replace

How do you convert a string such as `2009-05-08 14:40:52,531` into a `DateTime`?

Converting a String to DateTime

I come from a php background and in php, there is an `array_size()` function which tells you how many elements in the array are used. 

Is there a similar method for a `String[]` array? Thanks.

Java String array: is there a size of method?

When I do this:

    std::vector&lt;int&gt; hello;

Everything works great. However, when I make it a vector of references instead:

    std::vector&lt;int &amp;&gt; hello;

I get horrible errors like 

&gt; error C2528: &#39;pointer&#39; : pointer to reference is illegal

I want to put a bunch of references to structs into a vector, so that I don&#39;t have to meddle with pointers. Why is vector throwing a tantrum about this? Is my only option to use a vector of pointers instead?

Why can&#39;t I make a vector of references?

I need to check whether an std:string begins with &quot;xyz&quot;. How do I do it without searching through the whole string or creating temporary strings with substr().

std::string comparison (check whether string begins with another string)

Can someone please tell me the point of the STL heap function templates like `std::make_heap`? Why would anyone ever use them? Is there a practical use?

What is the point of make_heap?

I mean, aside from its obligating name (the Standard Template Library)...

C++ initially intended to present OOP concepts into C. That is: you could tell what a specific entity could and couldn&#39;t do (regardless of how it does it) based on its class and class hierarchy. Some compositions of abilities are more difficult to describe in this manner due to the problematics of multiple inheritance, and the fact that C++ supports the concept of interfaces in a somewhat clumsy way (compared to java, etc), but it&#39;s there (and could be improved).

And then templates came into play, along with the STL. The STL seemed to take the classical OOP concepts and flush them down the drain, using templates instead.

There should be a distinction between cases when templates are used to generalize types where the types themeselves are irrelevant for the operation of the template (containers, for examples). Having a `vector&lt;int&gt;` makes perfect sense.

However, in many other cases (iterators and algorithms), templated types are supposed to follow a &quot;concept&quot; (Input Iterator, Forward Iterator, etc...) where the actual details of the concept are defined entirely by the implementation of the template function/class, and not by the class of the type used with the template, which is a somewhat anti-usage of OOP.

For example, you can tell the function:

    void MyFunc(ForwardIterator&lt;...&gt; *I);

**Update:** As it was unclear in the original question, ForwardIterator is ok to be templated itself to allow any ForwardIterator type. The contrary is having ForwardIterator as a concept.

expects a Forward Iterator only by looking at its definition, where you&#39;d need either to look at the implementation or the documentation for:

    template &lt;typename Type&gt; void MyFunc(Type *I);


Two claims I can make in favor of using templates: compiled code can be made more efficient, by tailor-compiling the template for each used type, instead of using vtables. And the fact that templates can be used with native types.

However, I am looking for a more profound reason why abandoning classical OOP in favor of templating for the STL? (Assuming you read that far :P)

Why is the C++ STL is so heavily based on templates? (and not on *interfaces*)

For example, say I have a class Temp:

    class Temp
    {
        public:
            int function1(int foo) { return 1; }
            void function2(int bar) { foobar = bar; }
    
        private:
            int foobar;
    };

When I create an object of class Temp, how would I calculate how much space it needs, and how is it represented in memory (e.g.| 4 bytes for foobar| 8 bytes for function1 | etc | )


How do you determine the size of an object in C++?

I have a JTable in which I set the column size as follows:

	table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
	table.getColumnModel().getColumn(0).setPreferredWidth(27);
	table.getColumnModel().getColumn(1).setPreferredWidth(120);
	table.getColumnModel().getColumn(2).setPreferredWidth(100);
	table.getColumnModel().getColumn(3).setPreferredWidth(90);
	table.getColumnModel().getColumn(4).setPreferredWidth(90);
	table.getColumnModel().getColumn(6).setPreferredWidth(120);
	table.getColumnModel().getColumn(7).setPreferredWidth(100);
	table.getColumnModel().getColumn(8).setPreferredWidth(95);
	table.getColumnModel().getColumn(9).setPreferredWidth(40);
	table.getColumnModel().getColumn(10).setPreferredWidth(400);

This works fine, but when the table is maximized, I get empty space to the right of the last column. Is it possible to make the last column resize to the end of the window when resized?

I found `AUTO_RESIZE_LAST_COLUMN` property in docs but it does not work.

Edit: `JTable` is in a `JScrollPane` its prefered size is set.

Java JTable setting Column Width

My current situation is: I have to read a file and put the contents into `InputStream`. Afterwards I need to place the contents of the `InputStream` into a byte array which requires (as far as I know) the size of the `InputStream`. Any ideas?

As requested, I will show the input stream that I am creating from an uploaded file

    InputStream uploadedStream = null;
    FileItemFactory factory = new DiskFileItemFactory();
    ServletFileUpload upload = new ServletFileUpload(factory);
    java.util.List items = upload.parseRequest(request);	  
    java.util.Iterator iter = items.iterator();
	  
    while (iter.hasNext()) {
        FileItem item = (FileItem) iter.next();
        if (!item.isFormField()) {
            uploadedStream = item.getInputStream();
            //CHANGE uploadedStreambyte = item.get()
        }
    }
The request is a `HttpServletRequest` object, which is like the `FileItemFactory` and `ServletFileUpload` is from the Apache Commons FileUpload package.

Determine the size of an InputStream

This may have been answered elsewhere but I could not find a suitable response.

I have this code:

    enum enumWizardPage
    {
    	WP_NONE = 0x00,  
    	WP_CMDID = 0x01,	
    	WP_LEAGUES = 0x02,	
    	WP_TEAMS = 0x04,	
    	WP_COMP = 0x08,	
    	WP_DIVISIONS = 0x10,
    	WP_FORMULAS = 0x20,	
    	WP_FINISHED = 0x40,	
    };

Which is legacy and I have to modify it by adding a few new values.
The issue is each value must be a unique bit so they may be OR combined to a bitmap.

The values are set using the #x## hex format, but I&#39;m wondering if this is the max it can store?
What will be the effect, if any, if I change my code to 

    enum enumWizardPage
    {
    	WP_NONE = 0x0000,  
    	WP_CMDID = 0x0001,	
    	WP_LEAGUES = 0x0002,	
    	WP_TEAMS = 0x0004,	
    	WP_COMP = 0x0008,	
    	WP_DIVISIONS = 0x0010,
    	WP_FORMULAS = 0x0020,	
    	WP_FINISHED = 0x0040,	
    };


What is the underlying type of a c++ enum?

Is there a way in C to find out the size of dynamically allocated memory?     

For example, after

    char* p = malloc (100);

Is there a way to find out the size of memory associated with `p`?

Content Type	Original Author	Original Content on Stackoverflow
Question	Naveen	View Question on Stackoverflow
Solution 1 - C++	Todd Gamblin	View Answer on Stackoverflow
Solution 2 - C++	Alex Martelli	View Answer on Stackoverflow
Solution 3 - C++	Morten	View Answer on Stackoverflow
Solution 4 - C++	user7817690	View Answer on Stackoverflow

std::string length() and size() member functions

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Solution 3 - C++

Solution 4 - C++

how to set radio option checked onload with jQuery

How to pass command line arguments to a shell alias?

Attributions