The sort method can be used to sort the elements of a JavaScript array. By default, elements of an array are sorted in alphabetical order.
var aryTest = ['nash','boozer','duncan'];
document.write(aryTest.sort());
The preceding example sorts an array alphabetically.
To sort a JavaScript array by some order other than alphabetical, a comparison function is needed.
function SortNumbers(a,b)
{
return a-b;
}
var aryTest = [10,20,15,5];
document.write(aryTest.sort(SortNumbers));
The preceding example defines a function on which to base the sorting of the array and then executes the sort based on that comparison function. The comparison function needs to return:
A negative number if a is less than b.
A positive number if a is greater than b.
0 if a and b are equal.
To sort the array of numbers in a descending order, simply the reverse the math to b-a in the comparison function, as follows:
function SortNumbers(a,b)
{
return b-a;
}
var aryTest = [10,20,15,5];
document.write(aryTest.sort(SortNumbers));
