Core PHP Programming: Using PHP to Build Dynamic Web Sites

Retrieving Values

To use the value stored in a variable, use it anywhere where a value is required, such as the argument to a function or in an expression. For example, if you wish to print the value to the browser, you can type print($s) to print the value of a variable named s. You can even set a variable with the value of another, such as $s = $t.

If a variable contains a string, you may refer to each character using square brackets. Each character is numbered starting with zero. To refer to the seventh character in the s variable, you would type $s[6]. This notation works both ways, in fact. You can set a single character of a string with an expression like $s[6] ="x". Only the first character of the value on the right-hand side will be used ...