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  1. <?php
  2. function callback1($m) {return c($m[1]);}
  3. function callback2($n,$m) {
  4.     $o=$m[0];
  5.     $m[0]=' ';
  6.     return $o=='+' ? $n+$m : ($o=='-' ? $n-$m : ($o=='*' ? $n*$m : $n/$m));
  7. }
  8. function c($s){ 
  9.     while ($s != ($t = preg_replace_callback('/\(([^()]*)\)/','callback1',$s))) $s=$t;
  10. 		preg_match_all('![-+/*].*?[\d.]+!', "+$s", $m);
  11. 		return array_reduce($m[0], 'callback2');
  12. }
  13.  
  14. $str = '(3 + 2) * 5';
  15. echo c($str);
Success #stdin #stdout 0.01s 52488KB
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https://ideone.com/L9Ayib
language:
PHP (php 7.3.5)
created:
8 years ago
visibility:
public

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