Why does this PHP function return the wrong result?

Question

I wrote a user function to return the distance between two points on an x,y coordinate system. The input params were 0,0,10,10 .

Here is the original code:

public static function dist2d($x1,$y1,$x2,$y2) {
   return sqrt((($x2 - $x1) * ($x2 - $x1)) + (($y2 - $y1) * ($y2 - $y1)));
}

This returns 110.

Here is the code that works:

public static function dist2d($x1,$y1,$x2,$y2) {
    $result = (($x2 - $x1) * ($x2 - $x1)) + (($y2 - $y1) * ($y2 - $y1));
    return sqrt($result);
}

This returns 14.1 .

I am new to PHP, what is going on here?

Answer 1

这两个函数都返回14.142135623731。

Answer 2

Are you sure about that? It's pretty strange because the two functions are identical.

I tried both of them in my environment (using cut & paste from your question) and both return 14.142135623731.

Answer 3

你的PHP的特定版本一定是奇怪的，因为我的工作正常（5.3.3）。

Answer 4

You have probably made some kind of typo - both versions work for me correctly (please see http://codepad.org/1gFCTPfU as evidence).

Plus, if you are not describing static method of some class, you should replace public static function dist2d( with function dist2d( , otherwise you will get parse error as here: http://codepad.org/GkMfFqlo