PHP through the function_exists detection of the existence of methods _php skills

This article is an example of how PHP can detect the existence of a function through function_exists. Share to everyone for your reference. The specific analysis is as follows:

PHP can detect the existence of another function through the function_exists () function, you can pass the function name as a string into the function_exists to determine whether or not there

Function Highlight ($txt) {return
  "<sub> $txt </sub>";
}
function TextWrap ($tag, $txt, $func = "") {
 if (function_exists ($func))
  $txt = $func ($txt);
  Return "< $tag > $txt </$tag >\n";
}

Examples of usage are as follows:

echo textwrap (' i ', ' function exists Demo ', ' highlight ');
Output is in italics: function exists Demo

I hope this article will help you with your PHP program design.