PHP method to detect whether a function exists through function_exists, phpfunction_exists_PHP tutorial

php method to detect the existence of a function through function_exists, phpfunction_exists

The example in this article describes the method of php to detect the existence of a function through function_exists. Share it with everyone for your reference. The specific analysis is as follows:

In PHP, you can use the function_exists() function to detect whether another function exists. You can pass the function name as a string into function_exists to determine whether it still exists

function highlight( $txt ) {
  return "<sub>$txt</sub>";
}
function textWrap( $tag, $txt, $func="" ) {
 if (function_exists( $func ) )
  $txt = $func($txt);
  return "<$tag>$txt</$tag>\n";
}

Usage examples are as follows:

echo textWrap('i','function exists Demo','highlight');
//输出结果为斜体字的： function exists Demo

I hope this article will be helpful to everyone’s PHP programming design.