функции пхп
Здравствуйте уважаемые, у меня такая проблема, при написании программы на пхп, появилась необходимось вычислять выражения, записанные в строковом типе, есть ли в пхп такая функция, а то не хочеться вычислять её через js(eval)
RTFM! RTFM! RTFM!!!
http://wm-help.net/books-online/book/15200/15200-697.html
http://wm-help.net/books-online/book/15200/15200-697.html
eval
(PHP 3, PHP 4, PHP 5)
eval -- Evaluate a string as PHP code
Description
mixed eval ( string code_str )
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. To mix HTML output and PHP code you can use a closing PHP tag to leave PHP mode.
Also remember that variables given values under eval() will retain these values in the main script afterwards.
Parameters
code_str
The code string to be evaluated. code_str does not have to contain PHP Opening tags.
A return statement will immediately terminate the evaluation of the string .
Return Values
As of PHP 4, eval() returns NULL unless return is called in the evaluated code, in which case the value passed to return is returned. In case of a parse error in the evaluated code, eval() returns FALSE.
In PHP 3, eval() does not return a value.
(PHP 3, PHP 4, PHP 5)
eval -- Evaluate a string as PHP code
Description
mixed eval ( string code_str )
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. To mix HTML output and PHP code you can use a closing PHP tag to leave PHP mode.
Also remember that variables given values under eval() will retain these values in the main script afterwards.
Parameters
code_str
The code string to be evaluated. code_str does not have to contain PHP Opening tags.
A return statement will immediately terminate the evaluation of the string .
Return Values
As of PHP 4, eval() returns NULL unless return is called in the evaluated code, in which case the value passed to return is returned. In case of a parse error in the evaluated code, eval() returns FALSE.
In PHP 3, eval() does not return a value.