How to Append Something to an Array

How to append something to an array?

Use the Array.prototype.push method to append values to the end of an array:

// initialize array
var arr = [
  "Hi",
  "Hello",
  "Bonjour"
];

// append new value to the array
arr.push("Hola");

console.log(arr);

Can someone explain how to append an element to an array in C programming?

int arr[10] = {0, 5, 3, 64};
arr[4] = 5;

EDIT:
So I was asked to explain what's happening when you do:

int arr[10] = {0, 5, 3, 64};

you create an array with 10 elements and you allocate values for the first 4 elements of the array.

Also keep in mind that arr starts at index arr[0] and ends at index arr[9] - 10 elements

arr[0] has value 0;
arr[1] has value 5;
arr[2] has value 3;
arr[3] has value 64;

after that the array contains garbage values / zeroes because you didn't allocated any other values

But you could still allocate 6 more values so when you do

arr[4] = 5;

you allocate the value 5 to the fifth element of the array.

You could do this until you allocate values for the last index of the arr that is arr[9];

Sorry if my explanation is choppy, but I have never been good at explaining things.

Is there a way to append an array of objects in processing?

From the docs page you linked in your question:

When using an array of objects, the data returned from the function
must be cast to the object array's data type. For example: SomeClass[]
items = (SomeClass[]) append(originalArray, element).

In your example that would look like this:

PLANETS = (planet[]) append(PLANETS, tb);

The (planet[]) part is just telling Processing to cast the element returned from append as an array of planet objects.

Append an element to Array of Arrays

You are looking for np.insert.
https://numpy.org/doc/stable/reference/generated/numpy.insert.html

np.insert(x, 0, [10,10,10], axis=1)

How to extend an existing JavaScript array with another array, without creating a new array

The .push method can take multiple arguments. You can use the spread operator to pass all the elements of the second array as arguments to .push:

>>> a.push(...b)

If your browser does not support ECMAScript 6, you can use .apply instead:

>>> a.push.apply(a, b)

Or perhaps, if you think it's clearer:

>>> Array.prototype.push.apply(a,b)

Please note that all these solutions will fail with a stack overflow error if array b is too long (trouble starts at about 100,000 elements, depending on the browser).

If you cannot guarantee that b is short enough, you should use a standard loop-based technique described in the other answer.

How to add new elements to an array?

The size of an array can't be modified. If you want a bigger array you have to instantiate a new one.

A better solution would be to use an ArrayList which can grow as you need it. The method ArrayList.toArray( T[] a ) gives you back your array if you need it in this form.

List<String> where = new ArrayList<String>();
where.add( ContactsContract.Contacts.HAS_PHONE_NUMBER+"=1" );
where.add( ContactsContract.Contacts.IN_VISIBLE_GROUP+"=1" );

If you need to convert it to a simple array...

String[] simpleArray = new String[ where.size() ];
where.toArray( simpleArray );

But most things you do with an array you can do with this ArrayList, too:

// iterate over the array
for( String oneItem : where ) {
    ...
}

// get specific items
where.get( 1 );

When I append something to my array it doesn't add anything to the list

Append returns a new IEnumerable. It does not add to the OBJECTS, but essentially returns a new list. You have to capture the result of Append and use that: var extendedList = OBJECTS.Append(reg).

A better way is to use a list and use Add instead of Append. It is faster and cleaner.

How to append elements to all items in an array

You need to clone that element, and please don't use an ID, otherwise you'll end up having duplicated IDs.

const ELS_menuItems = document.querySelectorAll('.menu-item');
const EL_deleteButton = document.querySelector('#deleteButton');

ELS_menuItems.forEach(EL_item => EL_item.append(EL_deleteButton.cloneNode(true)));  
// Be advised that you'll end up having duplicated IDs in your DOM now

• https://developer.mozilla.org/en-US/docs/Web/API/NodeList/forEach
• https://developer.mozilla.org/en-US/docs/Web/API/Node/cloneNode
• https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll

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