JS Array definition

JS Array definition
Foreign sites to get down some of the JS array operation implementation, this tutorial is mainly defined in this regard.
var arr = new Array ();
var arr = new Array ([length]);
var arr = [Element1, Element2, ..., ELEMENTN];

In both cases the ARR variable is a array that has three element:a, B, C
var arr = new Array ("A", "B", "C");
Or
var arr = ["A", "B", "C"];

You can access the elements of the array by zero-based indices
var firstitem = arr[0]; A
var thirditem = arr[2]; C

You can get the length of the ' array by the ' Length property
var len = arr.length; 3

Example Two

var arr1 = new Array ("A", "B", "C");
var arr2 = new Array (1, 2, 3);
var Multiarr = new Array (arr1, ARR2);
Or
var Multiarr = [arr1, arr2];
Or
var multiarr = [["A", "B", "C"], [1, 2, 3]];

You can access the elements of the array by zero-based indices
var firstrow = multiarr[0]; Same as Arr1
var Secondrowfirstcell = multiarr[1][0]; 1

Three
var arr = ["A", "B", "C"];

Display the elements of the array (ABC)
for (var i = 0; i < arr.length; i++) {
document.write (Arr[i]);
}

Iterating with the for in statement, I'll be 0, 1, 2.
The output would be ABC
for (var i in arr) {
document.write (Arr[i]);
}
Four
We must create an array:
var arr = [];
Add elements at the position:
Arr[0] = "A";
ADD elements at the second position:
ARR[1] = "B";
Adding an element to the end of the array:
Arr.push ("C");
Now the ARR variable is a array that have three elements:a,b,c.

Five

var arr1 = ["A", "B", "C"];
var arr2 = [1, 2, 3];
Concat the arrays:
var newArr = Arr1.concat (ARR2);

Six

var arr = ["A", "B", "C"];
document.write (arr); Output:a,b,c

Arr.splice (1, 1);
document.write ("<br/>");
document.write (arr); Output:a,c

Seven
var arr = {};
Can add elements to a associative array in two different ways:
arr["Name" = "John";
arr["location"] = "Utah";
Second Way
Arr.age = 13;

You can access the elements of this array by string indices
var loc = arr["Location"]; "Utah"
Or like a
var loc = arr.location; "Utah"

You are cannot get the length of the array via the
It contains an invalid value
var len = arr.length; Len would

Eight
var arr = {};
arr["Name" = "John";
arr["location"] = "Utah";
Arr["age"] = 13;

Iterating with the for in statement, I'll be ' name ', ' Location ', ' age '.
The output would be JohnUtah13
for (var i in arr) {
document.write (Arr[i]);
}

Nine

var arr = {};
arr["Name" = "John";
arr["location"] = "Utah";
Arr["age"] = 13;
Display the initial contents of the array, Output:johnutah13
for (var i in arr) {
document.write (Arr[i]);
}

Delete arr.location; Delete the Location property from the array
document.write ("<br/>");
Display the current contents of the array, output:john13
for (var i in arr) {
document.write (Arr[i]);
}