Question

Tested in PHP 5.3.10 on CentOS.

In a script a run:

$test = "62 3/4";

if($pos = strpos($test,' ') !== false) {
  $test= substr($test,0,$pos); // use $pos
}
// $test is "6"

And in another independent script I run:

if($pos = strpos($test,' ') !== false) {
  $test = substr($test,0,strpos($test,' ')); // redo substr calculation
}
// $test is "62"

$pos should be 2 (the third character is a space, starting from zero, 0,1,2), so both $test should be “62”, no?

Answer 1

Operator precedence! !== comes before =, so the test effectively becomes

if($pos = (strpos($test,' ') !== false))

which is going to evaluate to either true or false, not the string position.

Always use explicit parens:

if(($pos = strpos($test,' ') !== false)