Call a Function by Its Name as a String in PHP

In PHP, it is possible to call a function by its name as a string. This can be useful when the name of the function is not known until runtime, or when the name of the function is stored in a variable or retrieved from a database or other external source.

To call a function by its name as a string, the string containing the function name can be used as a function call. For example, if the string containing the function name is $func, the function can be called like this:

$func();

This will call the function with the name stored in $func.

Another way to call a function by its name as a string is to use the call_user_func() function. This function takes a callback function as its first argument, which can be specified as a string containing the name of the function to be called. For example, the following code will call the function with the name stored in $func using call_user_func():

call_user_func($func);

The call_user_func() function also supports more advanced usage patterns, such as calling a method of an object with parameters. For example, the following code will call the function named $func on the object $obj, passing the parameters stored in $params:

call_user_func(array($obj, $func), $params);

In this example, the array($obj, $func) argument specifies the method to call, and the $params argument specifies the parameters to pass to the method.

In summary, there are two ways to call a function by its name as a string in PHP: by using the string containing the function name as a function call, or by using the call_user_func() function. The latter method provides more flexibility and allows for more advanced usage patterns, such as calling methods of objects with parameters.