如何动态传递if语句的条件

I am in a situation where I'll get comparison string in a variable, and I want to use that variable in IF

$xyz = '$abc<200'; // Dummy Dynamic Text

if($xyz) { // It should execute like if($abc<200)
    echo 'you are dynamic';
}

In the example above the comparison string coming dynamically in $xyz variable and I want to put that variable in if condition, How do I do that?

You cannot use quotes as it is making the string out of it. Do it this way:

$xyz=($abc<200); //or, as well, $xyz=$abc<200
if($xyz) { 
    echo 'you are dynamic'; 
}

If however you want to keep that condition text in string, you could use eval:

$xyz='$abc<200';
if(eval("return $xyz;")) { 
    echo 'you are dynamic'; 
}

Eval is sometimes disabled. This is for security reasons. Often with suhosin. Eval can be evil! Think about code injections.

You could try to use an anonymous function.

<?php

$func = function($abc) {
  return $abc<200;
};


if ($func($abc)) {
   // great
}