**Alloc:** Class method of NSObject. Returns a new instance of the receiving class.
 
**Init**: Instance method of NSObject. Implemented by subclasses to initialize a new object (the receiver) immediately after memory for it has been allocated.

**New**: Class method of NSObject. Allocates a new instance of the receiving class, sends it an init message, and returns the initialized object.

**Release**: Instance method of NSObject delegate. Decrements the receiver’s reference count.

**Autorelease**: Instance method of NSObject delegate. Adds the receiver to the current autorelease pool.

**Retain:** Instance method of NSObject delegate. Increments the receiver’s reference count.

**Copy:** Instance method of NSObject delegate. Returns a new instance that’s a copy of the receiver.

So to conclude we can say that 

**alloc goes with init**

**new = alloc + init**

The `+new` method is simply shorthand for `+alloc` and `-init`. The ownership semantics are identical. The only benefit to using `+new` is that it is more concise. If you need to provide arguments to the class&#39;s initialiser, you will have to use the `+alloc` and `-initWith...` methods instead.

Here: https://stackoverflow.com/questions/3330963/alloc-init-and-new-in-objective-c

Basically it&#39;s a question of modern versus traditional. The most direct advantage of init over new is that there are many custom init methods. 

We have several JavaScript files which we load at the bottom of the master page. However, I have the situation that I need to perform some JavaScript before the other scripts are loaded. Is it possible to wait till all the JavaScript files are loaded and then execute some JavaScript code?

I thought `$(document).ready()` did this, but as it turns out, it doesn&#39;t. Of course we can move the script files from the bottom to the top, but I am wondering if it&#39;s possible what I want.

Is it possible to wait until all javascript files are loaded before executing javascript code?

My array looks like this:

    array(
      0 =&gt; &#39;val&#39;,
      2 =&gt; &#39;val&#39;,
      3 =&gt; &#39;val&#39;,
      5 =&gt; &#39;val&#39;,
      7 =&gt; &#39;val&#39;
    );

How can I reset the keys so it will go like `0, 1, 2, 3, 4`?

How to reindex an array?

&gt; **Possible Duplicate:**  
&gt; [alloc, init, and new in Objective-C](https://stackoverflow.com/questions/3330963/alloc-init-and-new-in-objective-c)  

&lt;!-- End of automatically inserted text --&gt;

I am a little confused about `[Class new]` and  `[[Class alloc] init]`. I have defined an object `content` using `[Class new]` and  `[[Class alloc] init]`.

    (1). NSMutableArray *content = [NSMutableArray new];
    (2). NSMutableArray *content = [[NSMutableArray alloc] init];

My question is about the differences between `[Class new]` and `[[Class alloc] init]`. For me, (1) and (2) are similar. If (1) and (2) are similar, then why do we use `[[Class alloc] init]` most of the time, compared to `[Class new]`? I think that there must be some difference. 

Kindly explain the differences, pros &amp; cons of both?

What is the difference between [Class new] and [[Class alloc] init] in iOS?

> Possible Duplicate: 
> <a href="https://stackoverflow.com/questions/3330963/alloc-init-and-new-in-objective-c" target="_blank" rel="noopener noreferrer">alloc, init, and new in Objective-C</a>

I am a little confused about <code>[Class new]</code> and <code>[[Class alloc] init]</code>. I have defined an object <code>content</code> using <code>[Class new]</code> and <code>[[Class alloc] init]</code>.
<pre><code class="hljs language-ini">(1). NSMutableArray *content = [NSMutableArray new];
(2). NSMutableArray *content = [[NSMutableArray alloc] init];
</code></pre>
My question is about the differences between <code>[Class new]</code> and <code>[[Class alloc] init]</code>. For me, (1) and (2) are similar. If (1) and (2) are similar, then why do we use <code>[[Class alloc] init]</code> most of the time, compared to <code>[Class new]</code>? I think that there must be some difference.
Kindly explain the differences, pros &#x26; cons of both?

I&#39;m not sure this is a suitable question for here but is the new Chrome app for IOS just a UIWebView?

If so then would it be safe to assume that there shouldn&#39;t be any rendering differences between it and mobile Safari?

Chrome IOS - Is it just a UIWebView?

Surely an ordered set is a more-specific case of a set, so why does `NSOrderedSet` inherit from `NSObject` rather than `NSSet`?

Why doesn&#39;t NSOrderedSet inherit from NSSet?

When I try to submit my app on the App Store through Xcode I got this&#160;error.

&gt; A server with the specified hostname could not be found.

Is this temporary error at Apple or something to do with&#160;Xcode?

Is anyone else facing this problem?

A server with the specified hostname could not be found

I have a UIView, it is not inside UIScrollView. I would like to move up my View when the keyboard appears. Before I tried to use this solution: https://stackoverflow.com/questions/1126726/how-to-make-a-uitextfield-move-up-when-keyboard-is-present.

It was working fine. But after inserting the data in the textfields, it takes me to another view, and when I get back to this page, its just jumping, and I couldn&#39;t see my text fields. Is there any better solution for this problem?

Move UIView up when the keyboard appears in iOS

The height in portrait and the height in landscape measured in points.

What is the height of iPhone&#39;s onscreen keyboard?

I&#39;ve encountered a problem where my button should remain &quot;pressed down&quot; while it shows popover called from it. Popover is selector for some filter and filter is shown on button itself. When I tap on it and it shows popover it becomes deselected no matter what.

I think I have to redefine it&#39;s behavior on touch event and make it respond not to standart `touch up inside`. Then I wondered what are other events responsible for? But I couldn&#39;t find events list in iOS library and in StackOverflow are only questions about incorrect behavior of `touch up inside` or `touch down`.

So what&#39;s the difference betweeen touch events?

 1. touch cancel - when you touch button but move your finger away and
    it remains deselected? 
 2. touch down - right on tap.
 3. touch down repeat ?? 
 4. touch drag enter ??
 5. touch drag exit ?? 
 6. touch drag inside ?? 
 7. touch drag outside ?? 
 8. touch up inside - when you tap and release button remaining in it&#39;s
    bounds . It changes UIButtons state to Normal.
 9. touch up outside - when you tap and release button leaving it&#39;s
    bounds ?

other IBActions are not sent by UIButton, right?
Also how those events change UIButton&#39;s appearance? Like `highlighted` or `selected`?

I&#39;d appreciate a link on good article about IBActions, because I couldn&#39;t find it.

UIButton events. What&#39;s the difference?

My application crashed with the reason:

&gt; -[MyClassName copyWithZone:]  unrecognized selector sent to instance

I have two classes. Let&#39;s say Class1 and Class2.

Class1 looks like:

###Class1.h

    @interface Class1 : NSObject {
        NSString *imagemd5CheckSum;
        UIImage *image;
        NSData *fileChunkData;
    }

    @property (nonatomic, copy)NSString *imagemd5CheckSum;
    @property (nonatomic, copy)UIImage *image;
    @property (nonatomic, copy)NSData *fileChunkData;

    @end


###Class1.m

    @implementation Class1

    @synthesize image;
    @synthesize fileChunkData;
    @synthesize imagemd5CheckSum;

    -(id) init{
        [self setImage:nil];
        [self setFileChunkData:nil];
        [self setImagemd5CheckSum:@&quot;&quot;];

        return self;
    }

    -(void)dealloc{
        [imagemd5CheckSum release];
        [image release];
        [fileChunkData release];

        fileChunkData = nil;
        imagemd5CheckSum = nil;
        image = nil;

        [super dealloc];
    }
    @end

**

&gt; Class2 looks like

**

###Class2.h
*********

    #import &quot;Class2.h&quot;
    @interface Class2 : NSObject {
        Class1 *obj1;
        Class1 *obj2;
        Class1 *obj3;
    }

    @property (nonatomic, copy)Class1 *obj1;
    @property (nonatomic, copy)Class1 *obj2;
    @property (nonatomic, copy)Class1 *obj3;

    @end

###Class2.m
********

    @implementation Class2

    @synthesize obj1,obj2,obj3;

    -(id) init{
        [self setObj1:nil];
        [self setObj2:nil];
        [self setObj3:nil];

        return self;
    }

    -(void)dealloc{
        [obj1 release];
        [obj2 release];
        [obj3 release];

        obj1 = nil;
        obj2 = nil;
        obj3 = nil;

        [super dealloc];
    }
    @end

###Crashed Situation

    Class2 *class2 = [[Class2 alloc] init];

    Class1 *class1 = [[Class1 alloc] init];

    [class1 setImagemd5CheckSum:@&quot;this is md5&quot;];
    [class1 setImage:myimage];
    [class1 setFileChunkData:myData];

    [class2 setObj1:class1]; // This line is crashed..

...

When I called `[class2 setObj1:class1];`, the application crashed with reason:

&gt; -[Class1 copyWithZone:]  unrecognized selector sent to instance

How can I fix this problem?


-[MyClassName copyWithZone:] unrecognized selector sent to instance

My client wants to share an image on Instagram, Twitter, Facebook.

I have done Twitter and Facebook but did not find any API or any thing on internet to share image on Instagram. **Is it possible to share image on Instagram? if yes then how?** 

When I check the developer site of Instagram I have found the Libraries of Ruby on Rails and Python. But there are no documentation of iOS Sdk

I have get token from instagram as per instagram.com/developer but now don&#39;t know what to do next step for sharing with instagram image.


How to share an image on Instagram in iOS?

I&#39;m reviewing someone else&#39;s C++ code for our project that uses MPI for high-performance computing (10^5 - 10^6 cores). The code is intended to allow for communications between (potentially) different machines on different architectures. He&#39;s written a comment that says something along the lines of:

&gt; We&#39;d normally use `new` and `delete`, but here I&#39;m using `malloc` and `free`. This is necessary because some compilers will pad the data differently when `new` is used, leading to errors in transferring data between different platforms. This doesn&#39;t happen with `malloc`.

This does not fit with anything I know from standard `new` vs `malloc` questions.

https://stackoverflow.com/questions/240212/what-is-the-difference-between-new-delete-and-malloc-free#240308 hints at the idea that the compiler could calculate the size of an object differently (but then why does that differ from using `sizeof`?).

https://stackoverflow.com/questions/8959635/malloc-placement-new-vs-new is a fairly popular question but only talks about `new` using constructors where `malloc` doesn&#39;t, which isn&#39;t relevant to this.

https://stackoverflow.com/questions/8752546/how-does-malloc-understand-alignment says that memory is guaranteed to be properly aligned with either `new` or `malloc` which is what I&#39;d previously thought.

My guess is that he&#39;s misdiagnosed his own bug some time in the past and deduced that `new` and `malloc` give different amounts of padding, which I think probably isn&#39;t true. But I can&#39;t find the answer with Google or in any previous question. 

Help me, StackOverflow, you&#39;re my only hope!

Malloc vs new -- different padding

Given availability of `make_unique` and `make_shared`, as well as automatic deletion by `unique_ptr` and `shared_ptr` destructors, what are the situations (apart from supporting legacy code) for using `new` and `delete` in C++14?

Are new and delete still useful in C++14?

In Go, what is the difference between `var s []int` and `s := make([]int, 0)`? 

I find that both works, but which one is better?

Declare slice or make slice?

I am making a simplistic [mark-and-compact garbage collector](https://gist.github.com/anonymous/79fb0bd4dc4d55e67e6b). Without going too much into details, the API it exposes is like this:

&lt;!-- language: lang-rust --&gt;

    /// Describes the internal structure of a managed object.
    pub struct Tag { ... }
    
    /// An unmanaged pointer to a managed object.
    pub type Pointer = *mut usize;
    
    /// Mapping from old to new locations.
    pub type Adjust = BTreeMap&lt;usize, Pointer&gt;;
    
    /// Mark this object and anything it points to as non-garbage.
    pub unsafe fn survive(ptr: Pointer);
    
    pub struct Heap { ... }
    
    impl Heap {
        pub fn new() -&gt; Heap;
        
        // Allocate an object with the specified structure.
        pub fn allocate(&amp;mut self, tag: Tag) -&gt; Pointer;
        
        /// Move all live objects from `heap` into `self`.
        pub unsafe fn reallocate(&amp;mut self, heap: Heap) -&gt; Adjust;
    }

This API is obviously fundamentally unsafe. I would like to rework the API (without changing the internals, which are just fine!) to account for the following facts:

1. All `Pointer`s to (objects allocated in) a `Heap` become invalid when the heap is `merge`d into another heap.

2. `merge` returns an `Adjust` whose values are valid `Pointer`s to (objects allocated in) `self`.

I have the following tentative solution:

&lt;!-- language: lang-rust --&gt;

    // Replaces Pointer.
    #[derive(Copy, Clone)]
    pub struct Object&lt;&#39;a&gt; {
        ptr: *mut AtomicUsize,
        mark: PhantomData&lt;&amp;&#39;a usize&gt;
    }
    
    impl&lt;&#39;a&gt; Object&lt;&#39;a&gt; {
        pub fn survive(self); // Now supposed to be perfectly safe!
    }
    
    pub type Adjust&lt;&#39;a&gt; = BTreeMap&lt;usize, Object&lt;&#39;a&gt;&gt;;
    
    pub struct Heap { ... }
    pub struct Allocator&lt;&#39;a&gt; { ... }
    
    impl Heap {
        fn allocator(&amp;&#39;a self) -&gt; Allocator&lt;&#39;a&gt;;
        // The following doesn&#39;t work:
        // 
        //  fn allocate(&amp;&#39;a mut self) -&gt; Object&lt;&#39;a&gt;;
        //  fn reallocate(&amp;&#39;a mut self, heap: Heap) -&gt; Adjust&lt;&#39;a&gt;;
        // 
        // Because it doesn&#39;t allow the user to allocate more
        // than one `Object` at a time (!) in a `Heap`.
    }
    
    impl&lt;&#39;a&gt; Allocator&lt;&#39;a&gt; {
        // Note that the resulting `Object`s are tied to the `Heap`,
        // but not to the allocator itself.
        fn allocate(&amp;mut self, tag: Tag) -&gt; Object&lt;&#39;a&gt;;
        fn reallocate(&amp;mut self, heap: Heap) -&gt; Adjust&lt;&#39;a&gt;;
    }

Is this design correct? If not, what needs to be changed?

Managing the lifetimes of garbage-collected objects

In a project, somebody pushed this line:

    double (*e)[n+1] = malloc((n+1) * sizeof(*e));

Which supposedly creates a two-dimensional array of (n+1)*(n+1) doubles.

*Supposedly*, I say, because so far, nobody I asked could tell me what this does, exactly, nor where it originated from or why it should work (which allegedly, it does, but I&#39;m not yet buying it).

Perhaps I&#39;m missing something obvious, but I&#39;d appreciate it if somebody could explain above line to me. Because personally, I&#39;d feel much better if we&#39;d use something we actually understand.


Freaky way of allocating two-dimensional array?

I&#39;m trying to follow [PEP 328][1], with the following directory structure:

    pkg/
      __init__.py
      components/
        core.py
        __init__.py
      tests/
        core_test.py
        __init__.py

In `core_test.py` I have the following import statement

    from ..components.core import GameLoopEvents

However, when I run, I get the following error:

    tests$ python core_test.py 
    Traceback (most recent call last):
      File &quot;core_test.py&quot;, line 3, in &lt;module&gt;
        from ..components.core import GameLoopEvents
    ValueError: Attempted relative import in non-package

Searching around I found &quot;https://stackoverflow.com/questions/9427037/relative-path-not-working-even-with-init-py&quot; and &quot;https://stackoverflow.com/questions/279237/python-import-a-module-from-a-folder/6098238#6098238&quot; but they didn&#39;t help.

Is there anything I&#39;m missing here?


  [1]: http://www.python.org/dev/peps/pep-0328/


How to fix &quot;Attempted relative import in non-package&quot; even with __init__.py

I&#39;ve tried to find a precise explanation of what the `init()` function does in Go. I read what [Effective Go][1] says but I was unsure if I understood fully what it said. The exact sentence I am unsure is the following:

&gt; And finally means finally: init is called after all the variable declarations in the package have evaluated their initializers, and those are evaluated only after all the imported packages have been initialized.

What does `all the variable declarations in the package have evaluated their initializers` mean? Does it mean if you declare &quot;global&quot; variables in a package and its files, init() will not run until all of it is evaluated and then it will run all the init function and then main() when ./main_file_name is ran?

I also read Mark Summerfield&#39;s go book the following:

&gt; If a package has one or more init() functions they are automatically executed before the main package&#39;s main() function is called.

In my understanding, `init()` is only relevant when you intend to run main() right? Anyone understands more precisely `init()` feel free to correct me

  [1]: https://golang.org/doc/effective_go.html#init

When is the init() function run?

*I hope that this question will not be marked as `primarily opinion-based`, but that there is an objective answer to it.*

I have read [Introducing dumb-init, an init system for Docker containers](https://engineeringblog.yelp.com/2016/01/dumb-init-an-init-for-docker.html), which extensively describes why and how to use `dumb-init`. To be honest, for someone not too experienced with how the Linux process structure works, this sounds pretty dramatic - and it feels as if you are doing things entirely wrong if you don&#39;t use `dumb-init`.

This is why I&#39;m thinking about using it within my very own Docker images… what keeps me from doing this is the fact that I have not yet found an official Docker image that uses it.

- Take [mongo](https://github.com/docker-library/mongo/blob/b5c66be72b21c54526b05c3ad99270ad8a0e3bcf/3.3/Dockerfile) as an example: They call `mongod` directly.
- Take [postgres](https://github.com/docker-library/postgres/blob/b1831ce069d10b14be05b9ddf6823e3d18c62cee/9.6/Dockerfile) as an example: They call `postgres` directly.
- Take [node](https://github.com/nodejs/docker-node/blob/9a4e5a31df1e7d1df8b3a2d74f23f340d5210ada/6.2/Dockerfile) as an example: They call `node` directly.
- …

If `dumb-init` is **so** important - why is apparently nobody using it? What am I missing here?

Content Type	Original Author	Original Content on Stackoverflow
Question	Prasad G	View Question on Stackoverflow
Solution 1 - Ios	Shantanu	View Answer on Stackoverflow
Solution 2 - Ios	dreamlax	View Answer on Stackoverflow
Solution 3 - Ios	OFRBG	View Answer on Stackoverflow

What is the difference between [Class new] and [[Class alloc] init] in iOS?

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

Solution 3 - Ios

How to reindex an array?

Is it possible to wait until all javascript files are loaded before executing javascript code?

Attributions