javascript variable as subscript in an array

Question

I can't find this answer anywhere. I am learning javascript on myself so I guess this is basic.

I want to assign a variable "count" as the subscript of an array.

var firstnumber = 200;
var count = 1;
var a;
a[count] = firstnumber;

therefore to achieve the result as a[count] = 200

is there anyway to do this?

Btw, if `a` was initialised as an array you'd have an array with two elements, `a[0] === undefined, a[1] === 200`. — Ja͢ck, May 16 '14 at 02:12

William Barbosa · Answer 1 · 2014-05-16T02:09:17.953

1

Declare your variable and initialize it as an array

var a = [];

edited May 16 '14 at 02:09

answered May 16 '14 at 01:59

William Barbosa

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That would be a [*VariableDeclaration*](http://ecma-international.org/ecma-262/5.1/#sec-12.2) with optional *intialiser*, in this case an [*Array initialiser*](http://ecma-international.org/ecma-262/5.1/#sec-11.1.4). :-) – RobG May 16 '14 at 02:05

score 0 · Answer 2 · answered May 16 '14 at 02:29

See the comments below:

var a = new Array();  //create an Array
var count = 0;  //arrays start at index 0
var firstnumber = 200;
var secondnumber = 300;

a[count] = firstnumber; //set the first element of the array to firstnumber

count = 1;
a[count] = secondnumber; //set the second element of the array to secondnumber

alert(a[0]);  //displays 200 in an alert window
alert(a[1]);  //displays 300 in an alert window

javascript variable as subscript in an array

2 Answers2