You can sort the existing arrays, or reorganize the data.
Method 1:
To use the existing arrays, you can combine, sort, and separate them:
(Assuming equal length arrays)
var names = ["Bob","Tom","Larry"];
var ages = ["10", "20", "30"];
//1) combine the arrays:
var list = [];
for (var j = 0; j < names.length; j++)
list.push({'name': names[j], 'age': ages[j]});
//2) sort:
list.sort(function(a, b) {
return ((a.name < b.name) ? -1 : ((a.name == b.name) ? 0 : 1));
//Sort could be modified to, for example, sort on the age
// if the name is the same.
});
//3) separate them back out:
for (var k = 0; k < list.length; k++) {
names[k] = list[k].name;
ages[k] = list[k].age;
}
This has the advantage of not relying on string parsing techniques, and could be used on any number of arrays that need to be sorted together.
Method 2: Or you can reorganize the data a bit, and just sort a collection of objects:
var list = [
{name: "Bob", age: 10},
{name: "Tom", age: 20},
{name: "Larry", age: 30}
];
list.sort(function(a, b) {
return ((a.name < b.name) ? -1 : ((a.name == b.name) ? 0 : 1));
});
for (var i = 0; i<list.length; i++) {
alert(list[i].name + ", " + list[i].age);
}
For the comparisons,-1 means lower index, 0 means equal, and 1 means higher index. And it is worth noting that sort() actually changes the underlying array.
Also worth noting, method 2 is more efficient as you do not have to loop through the entire list twice in addition to the sort.