public sortOn(fieldName:Object, [options:Object]) : Array

Sorts the elements in an array according to one or more fields in the array. The array should have the following characteristics:

• The array is an indexed array, not an associative array.
• Each element of the array holds an object with one or more properties.
• All of the objects have at least one property in common, the values of which can be used to sort the array. Such a property is called a field.

If you pass multiple fieldName parameters, the first field represents the primary sort field, the second represents the next sort field, and so on. Flash sorts according to Unicode values. (ASCII is a subset of Unicode.) If either of the elements being compared does not contain the field specified in the fieldName parameter, the field is assumed to be undefined, and the elements are placed consecutively in the sorted array in no particular order.

By default, Array.sortOn() works as described in the following list:

• Sorting is case-sensitive (Z precedes a).
• Sorting is ascending (a precedes b).
• The array is modified to reflect the sort order; multiple elements that have identical sort fields are placed consecutively in the sorted array in no particular order.
• Numeric fields are sorted as if they were strings, so 100 precedes 99, because "1" is a lower string value than "9".

You can use the options parameter to override the default sort behavior. If you want to sort a simple array (for example, an array with only one field), or if you want to specify a sort order that the options parameter doesn't support, use Array.sort().

To pass multiple flags, separate them with the bitwise OR (|) operator:

my_array.sortOn(someFieldName, Array.DESCENDING | Array.NUMERIC);

Parameters

fieldName:Object - A string that identifies a field to be used as the sort value, or an array in which the first element represents the primary sort field, the second represents the secondary sort field, and so on.

options:Object [optional] - One or more numbers or names of defined constants, separated by the | (bitwise OR) operator, that change the sorting behavior. The following values are acceptable for the options parameter:

• Array.CASEINSENSITIVE or 1
• Array.DESCENDING or 2
• Array.UNIQUESORT or 4
• Array.RETURNINDEXEDARRAY or 8
• Array.NUMERIC or 16

Code hinting is enabled if you use the string form of the flag (for example, DESCENDING) rather than the numeric form (2).

Returns

Array - The return value depends on whether you pass any parameters, as described in the following list:

• If you specify a value of 4 or Array.UNIQUESORT for the options parameter, and two or more elements being sorted have identical sort fields, Flash returns a value of 0 and does not modify the array.
• If you specify a value of 8 or Array.RETURNINDEXEDARRAY for the options parameter, Flash returns an array that reflects the results of the sort and does not modify the array.
• Otherwise, Flash returns nothing and modifies the array to reflect the sort order.

Example

The following example creates a new array and sorts it according to the name and city fields. The first sort uses name as the first sort value and city as the second. The second sort uses city as the first sort value and name as the second.

var rec_array:Array = new Array();
rec_array.push({name: "john", city: "omaha", zip: 68144});
rec_array.push({name: "john", city: "kansas city", zip: 72345});
rec_array.push({name: "bob", city: "omaha", zip: 94010});
for(i=0; i<rec_array.length; i++){
    trace(rec_array[i].name + ", " + rec_array[i].city);
}
// Results:
// john, omaha
// john, kansas city
// bob, omaha

rec_array.sortOn(["name", "city"]);
for(i=0; i<rec_array.length; i++){
    trace(rec_array[i].name + ", " + rec_array[i].city);
}
// Results:
// bob, omaha
// john, kansas city
// john, omaha

rec_array.sortOn(["city", "name" ]);
for(i=0; i<rec_array.length; i++){
    trace(rec_array[i].name + ", " + rec_array[i].city);
}
// Results:
// john, kansas city
// bob, omaha
// john, omaha

The following array of objects is used by subsequent examples that show how to use the options parameter:

var my_array:Array = new Array();
my_array.push({password: "Bob", age:29});
my_array.push({password: "abcd", age:3});
my_array.push({password: "barb", age:35});
my_array.push({password: "catchy", age:4});

Performing a default sort on the password field produces the following results:

my_array.sortOn("password");
// Bob
// abcd
// barb
// catchy

Performing a case-insensitive sort on the password field produces the following results:

my_array.sortOn("password", Array.CASEINSENSITIVE);
// abcd
// barb
// Bob
// catchy

Performing a case-insensitive, descending sort on the password field produces the following results:

my_array.sortOn("password", Array.CASEINSENSITIVE | Array.DESCENDING);
// catchy
// Bob
// barb
// abcd

Performing a default sort on the age field produces the following results:

my_array.sortOn("age");
// 29
// 3
// 35
// 4

Performing a numeric sort on the age field produces the following results:

my_array.sortOn("age", Array.NUMERIC);
// my_array[0].age = 3
// my_array[1].age = 4
// my_array[2].age = 29
// my_array[3].age = 35

Performing a descending numeric sort on the age field produces the following results:

my_array.sortOn("age", Array.DESCENDING | Array.NUMERIC);
// my_array[0].age = 35
// my_array[1].age = 29
// my_array[2].age = 4
// my_array[3].age = 3

When using the Array.RETURNEDINDEXARRAY sorting option, you must assign the return value to a different array. The original array is not modified.

var indexArray:Array = my_array.sortOn("age", Array.RETURNINDEXEDARRAY);

See also

| bitwise OR operator, sort (Array.sort method)