CODEWITHSUNDEEP
php
user950276
user950276

Reputation: 49

Simple function in PHP with Calculation

I am making very simple program in PHP . Tryig to addition first ..

But dont know ..

Here is code 

<?php 
$a=12;
$b=10;
$c="+";

$res=$a."$c".$b;
echo $res;
?>

it output 12+10 as it is concecate..

$c is anything.

Any idea how to do this

Upvotes: 0

Views: 150

Answers (3)

Joop Eggen
Joop Eggen

Reputation: 109547

Yes, also PHP has an eval(uate) function:

$res = eval($a . $c . $b);

Be sure that $a, $b and $c do not stem from form input, as eval can delete and so on.

Upvotes: 0

ComFreek
ComFreek

Reputation: 29424

What do you want to do exactly?

If you have the operator as a string, you could try a switch statement:

<?php 
$a=12;
$b=10;
$c="+";

switch($c) {
  case '+': 
      $res = $a + $b;
      break;

  case '-':
      $res = $a - $b;
      break;
}
var_dump($res);
?>

Upvotes: 2

Luc Franken
Luc Franken

Reputation: 3014

$c is now a string and not a expression "+" is not equal to +.

So:

$res=$a + $b;

If you would really need your structure you would have to do something evil like using eval() or you could do:

$a=12;
$b=10;
$operator='+';

switch($operator) {
  case '+':
    $res=$a + $b;
    break;
  case '-':
    $res=$a - $b;
    break;
}

Upvotes: 5

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