JavaScript tutorial:
length property (Array)

Applies to: Array Object

The lenght method return the value of the number of elements in the array.

Syntax

numVar = arrayObj.length

Return value

Returns an integer value one higher than the highest element defined in an array.

Example

As the elements in an array do not have to be contiguous, the length property is not necessarily the number of elements in the array. For example, in the following array definition, my_array.length contains 7, not 2:

var my_array = new Array( );
my_array[0] = "Test";
my_array[6] = "Another Test";

If a value smaller than its previous value is assigned to the length property, the array is truncated, and any elements with array indexes equal to or greater than the new value of the length property are lost.

If a value larger than its previous value is assigned to the length property, the array is expanded, and any new elements created have the value undefined.

The following example illustrates the use of the length property:

function Length() {     var a, l;     a = new Array(0,1,2,3,4);     l = a.length;     return(l); } document.write(Length());

To run the code above, paste it into JavaScript Editor, and click the Execute button

See also: length Property (Function), length Property (String)