Eval()

The eval() function executes a string as a PHP code.

eval() has been used originally to obtain features that PHP did not offer. Nowadays, those features are rare enough that it is recommended to find a safe alternative, before using on it.

When used, it is recommended to enclose eval() in a try-catch block, to catch syntax error.

<?php

    $name = 'v';
    $value = 'vvvv';

    // Set a variable with a dynamic name
    eval('$'.$name.' = '.$value);
    // equivalent to $$name = $value;

?>

Documentation

See also Eval function in PHP and The Land where PHP uses eval().

Related : ParseError, Try-catch, Code Injection, Execution