Variable variables
Variable variables
Sometimes it is convenient to be able to have variable variable names. That is, a variable name which can be set and used dynamically. A normal variable is set with a statement such as:
<?php $a = 'hello'; ?>
A variable variable takes the value of a variable and treats that as the name of a variable. In the above example, hello, can be used as the name of a variable by using two dollar signs. i.e.
<?php $$a = 'world'; ?>
At this point two variables have been defined and stored in the PHP symbol tree: $a with contents "hello" and 登录查看完整内容