myArray.sort( [ compareFunction ] ) in ECMAScript 262

The original array is sorted (modified), and a reference to the array is returned.

If no comparison function is supplied, toString() is called on each element of the array and a text-based, ascending-order comparison is used. For example:

var animals = [ 'ant' , 'cat' , 'boar' , 'aardvark' , 'elephant' ];
var numbers = [ 1 , 200 , 3 , 5 , 4 , 2 , 13 , 22 ];
animals.sort();   // ['aardvark','ant','boar','cat','elephant']
numbers.sort();   // [1,13,2,200,22,3,4,5]
// *** Numbers are converted to strings and compared as 'words' using the default sort

If a custom comparison function is supplied, it will be supplied two arguments, corresponding to two particular elements in the array to be sorted. The function must return -1 if the first argument should come before the second, 1 if it should come after the second argument, or 0 if the two arguments should be considered the same.

Following are two examples showing how to use a custom comparison function:

var numbers = [ 1 , 200 , 3 , 5 , 4 , 2 , 13 , 22 ];
function compareNumbers(a,b){
    return (a<b)?-1:(a>b)?1:0;

    //the above is the same as:
    //if (a<b) return -1;
    //else if (a>b) return 1;
    //else return 0
}
numbers.sort(compareNumbers);   // [1,2,3,4,5,13,22,200]

var people = [];
people.push( { name:'Bob' , age:15 , sex:'M' } );
people.push( { name:'Carol' , age:18 , sex:'F' } );
people.push( { name:'Sue' , age:33 , sex:'F' } );
people.push( { name:'Angie' , age:8 , sex:'F' } );
people.push( { name:'David' , age:12 , sex:'M' } );

people.sort( function(a,b){ return (a.age<b.age)?-1:(a.age>b.age)?1:0 } );
/************************************************************************
people is now:
[
    { name:'Angie', age:8, sex:'F' },
    { name:'David', age:12, sex:'M' },
    { name:'Bob', age:15, sex:'M' },
    { name:'Carol', age:18, sex:'F' },
    { name:'Sue', age:33, sex:'F' }
]
************************************************************************/

function compareSexThenName(a,b){
    if (a.sex<b.sex) return -1;
    else if (a.sex>b.sex) return 1;
    else return (a.name<b.name)?-1:(a.name>b.name)?1:0;
}
people.sort(compareSexThenName);
/************************************************************************
people is now:
[
    {name:'Angie', age:8, sex:'F'},
    {name:'Carol', age:18, sex:'F'},
    {name:'Sue', age:33, sex:'F'},
    {name:'Bob', age:15, sex:'M'},
    {name:'David', age:12, sex:'M'}
]
************************************************************************/

For a flexible convenience function to generate sorting functions for you, see SortBy.