Description
mixed eval
(string code_str)
eval() evaluates the string given in
code_str as PHP code. Among other things,
this can be useful for storing code in a database text field for
later execution.
There are some factors to keep in mind when using
eval(). Remember that the string passed must
be valid PHP code, including things like terminating statements
with a semicolon so the parser doesn't die on the line after the
eval(), and properly escaping things in
code_str.
Also remember that variables given values under
eval() will retain these values in the main
script afterwards.
A return statement will terminate the evaluation of
the string immediatley. In PHP4 you may use return
to return a value that will become the result of the
eval() function while in PHP3
eval() was of type void and did
never return anything.
Example 1.
Eval() example - simple text merge
<?php
$string = 'cup';
$name = 'coffee';
$str = 'This is a $string with my $name in it.<br>';
echo $str;
eval ("\$str = \"$str\";");
echo $str;
?>
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The above example will show:
This is a $string with my $name in it.
This is a cup with my coffee in it.
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