Why am I getting the output as 20 as I am getting 16 when I trace the code by myself?

Asked May 14 '19 at 14:56

Active May 14 '19 at 15:03

Viewed 43 times

I don't understand how the code editor gives me 20 as the output for the following PHP code:

<?php

  function sum2Numbers($x1)
  {
      static $x2 = 0;
      $x2 += $x1;
      return $x2;  
  }

  $sum = 10;

  for($m = 1; $m < 4; $m++)
    $sum += sum2Numbers($m); 

  echo $sum;
?>

I expect the output to be 16 but the actual output is 20. How?

edited May 14 '19 at 14:58

Ivar

6,138
12
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asked May 14 '19 at 14:56

ACM

1

https://3v4l.org/qIPtB 10 + 1 + 3 + 6 `$x2` is not starting off at 0 because you made it a static variable. – aynber May 14 '19 at 15:01
remove the static – LukeDS May 14 '19 at 15:02
1

The static variable, which is being updated with each call, maintains its value through multiple calls. – Chris White May 14 '19 at 15:02
1

Which is "the code editor"? Why do you expect the result to be 16? – Nico Haase May 14 '19 at 15:06
Static variable keeps value of last iteration in each function call. so for m=1, x2=0+1=1, sum=11. for m=2,x2=1+2=3, sum=14. for m=3,x2=3+3=6, sum=20. – Sarosh Khatana May 14 '19 at 15:28
@SaroshKhatana Thank u so much that explained a lot – ACM May 14 '19 at 15:58
Possible duplicate of [Static variables in PHP](https://stackoverflow.com/questions/7508284/static-variables-in-php) – miken32 May 14 '19 at 21:20

Why am I getting the output as 20 as I am getting 16 when I trace the code by myself?

0 Answers0