ADOBE® FLEX® 3: PROGRAMMING ACTIONSCRIPT™ 3.0

ADOBE FLEX 3

Developer Guide

134

Use the == and != operators to compare strings with each other and to compare strings with other types of objects,

as the following example shows:

var str1:String = "1";

var str1b:String = "1";

var str2:String = "2";

trace(str1 == str1b); // true

trace(str1 == str2); // false

var total:uint = 1;

trace(str1 == total); // true

Obtaining string representations of other objects

You can obtain a String representation for any kind of object. All objects have a toString() method for this

purpose:

var n:Number = 99.47;

var str:String = n.toString();

// str == "99.47"

When using the + concatenation operator with a combination of String objects and objects that are not strings, you

do not need to use the

toString() method. For details on concatenation, see the next section.

The

String() global function returns the same value for a given object as the value returned by the object calling

the

toString() method.

Concatenating strings

Concatenation of strings means taking two strings and joining them sequentially into one. For example, you can use

the

+ operator to concatenate two strings:

var str1:String = "green";

var str2:String = "ish";

var str3:String = str1 + str2; // str3 == "greenish"

You can also use the += operator to the produce the same result, as the following example shows:

var str:String = "green";

str += "ish"; // str == "greenish"

Additionally, the String class includes a concat() method, which can be used as follows:

var str1:String = "Bonjour";

var str2:String = "from";

var str3:String = "Paris";

var str4:String = str1.concat(" ", str2, " ", str3);

// str4 == "Bonjour from Paris"

If you use the + operator (or the += operator) with a String object and an object that is not a string, ActionScript

automatically converts the nonstring object to a String object in order to evaluate the expression, as shown in this

example:

var str:String = "Area = ";

var area:Number = Math.PI * Math.pow(3, 2);

str = str + area; // str == "Area = 28.274333882308138"