Add new value to an existing array in JavaScript [duplicate]

Answer 1

array = ["value1", "value2", "value3"]

it's not so much jquery as javascript

Answer 2

You don't need jQuery for that. Use regular javascript

var arr = new Array();
// or var arr = [];
arr.push('value1');
arr.push('value2');

Note: In javascript, you can also use Objects as Arrays, but still have access to the Array prototypes. This makes the object behave like an array:

var obj = new Object();
Array.prototype.push.call(obj, 'value');

will create an object that looks like:

{
    0: 'value',
    length: 1
}

You can access the vaules just like a normal array f.ex obj[0].

Answer 3

Array is a JavaScript native object, why don't you just try to use the API of it? Knowing API on its own will save you time when you will switch to pure JavaScript or another framework.

There are number of different possibilities, so, use the one which mostly targets your needs.

Creating array with values:

var array = ["value1", "value2", "value3"];

Adding values to the end

var array = [];
array.push("value1");
array.push("value2");
array.push("value3");

Adding values to the begin:

var array = [];
array.unshift("value1");
array.unshift("value2");
array.unshift("value3");

Adding values at some index:

var array = [];
array[index] = "value1";

or by using splice

array.splice(index, 0, "value1", "value2", "value3");

Choose one you need.

Answer 4

Indeed, you must initialize your array then right after that use array.push() command line.

var array = new Array();
array.push("first value");
array.push("second value");

Answer 5

jQuery is an abstraction of JavaScript. Think of jQuery as a sub-set of JavaScript, aimed at working with the DOM. That being said; there are functions for adding item(s) to a collection. I would use basic JavaScript in your case though:

var array;

array[0] = "value1";
array[1] = "value2";
array[2] = "value3";

... Or:

var array = ["value1", "value2", "value3"];

... Or:

var array = [];

array.push("value1");
array.push("value2");
array.push("value3");

Answer 6

There are several ways:

Instantiating the array:

var arr;

arr = new Array(); // empty array

// ---

arr = [];          // empty array

// ---

arr = new Array(3);
alert(arr.length);  // 3
alert(arr[0]); // undefined

// ---

arr = [3];
alert(arr.length);  // 1
alert(arr[0]); // 3

Pushing to the array:

arr = [3];     // arr == [3]
arr[1] = 4;    // arr == [3, 4]
arr[2] = 5;    // arr == [3, 4, 5]
arr[4] = 7;    // arr == [3, 4, 5, undefined, 7]

// ---

arr = [3];
arr.push(4);        // arr == [3, 4]
arr.push(5);        // arr == [3, 4, 5]
arr.push(6, 7, 8);  // arr == [3, 4, 5, 6, 7, 8]

Using .push() is the better way to add to an array, since you don't need to know how many items are already there, and you can add many items in one function call.