ActionScript: The Definitive Guide

Working with Strings

By manipulating strings we can program anything from a user-input validator to a word-scramble game. With a little ingenuity, we can make neat visual text effects and other fun stuff.

We can manipulate strings with both operators and built-in functions. String operators can join multiple strings together or compare the characters of two strings. Built-in functions can examine a string’s properties and contents, extract a portion of a string, check a character’s code point, create a character from a code point, change the case of the characters in a string, and even turn a string into a variable or property name.

Joining Strings Together

Joining strings together (creating a new string from two or more strings) is called concatenation. As seen earlier, we can concatenate two strings with the plus operator (+), like this:

"Macromedia" + "Flash"

That line of code yields the single string value “MacromediaFlash”. Oops! We forgot to put a space between the words. To add the space, we can insert it within the quotes that define one of the strings, such as:

"Macromedia " + "Flash"  // Yields "Macromedia Flash"

But that’s not always practical. In most cases we don’t want to add a space to a company or a product name. So instead, we join three strings together, the middle one of which is simply an empty space:

"Macromedia" + " " + "Flash"   // Also yields "Macromedia Flash"

Note that the space character is not the same as the empty string we saw earlier because the empty string has ...