How to call PHP function from string stored in a Variable

0 0 1 minute read

Given the names of some user-defined functions stored as strings in variables. The task is to call the functions using the names stored in the variables.

Example:

<?php 
  
// Function without argument  
function func() { 
    echo "geek"; 
} 
  
// Function with argument 
function fun($msg) { 
    echo $msg; 
} 
  
// Call func and fun using $var and $var1 
$var = "func"; 
$var1 = "fun";      
?> 

There are two methods for doing this. One is directly calling function by variable name using bracket and parameters and the other is by using call_user_func() Function but in both method variable name is to be used.

Program:

<?php 
  
// Function without argument  
function func() { 
    echo "hello "; 
} 
  
// Function with argument 
function fun($msg) { 
    echo $msg." "; 
} 
      
$var = "func"; 
$var1 = "fun";  
      
// 1st method by using variable name 
$var(); 
$var1("geek"); 
  
echo "\n"; 
  
// 2nd method by using php inbuilt 
// function call_user_func() 
call_user_func($var); 
call_user_func($var1, "fun_function");  
  
?> 

Output:

hello geek 
hello fun_function

Another Method: Using eval() Function: The eval() function is an inbuilt function in PHP which is used to evaluate string as PHP code.
Note: This method is contributed by Vineet Joshi.
Syntax:

eval( $code )

Parameters: This function accepts single parameter code which is used to hold the PHP code as a string.

Example:

<?php 
  
// Function without argument  
function writeMessage() { 
    echo "Welcome to zambiatek!"; 
} 
  
// Declare variable and store 
// function name     
$functionName = "writeMessage();"; 
  
// Function call using eval 
eval($functionName); 
?> 