length Property (Array)

See Also                 Applies To

Description

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

Syntax

numVar = arrayObj.length

Remarks

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