PHP字符串比较无法正常工作

Question

I am having an issue with PHP String comparison. It never turns out to be 0. Below I am trying to get a setting in a cookie and compare it with a given key, and return the value of that cookie. The cookies looks like this console=1|userId=5. The value is always -180 or something. I echo them out and the are the same, and the lengths are the same. Could it be an encoding issue?

$parameters = explode('|', $_COOKIE[Cisco_Rewards::REWARDS_SETTINGS_COOKIE_NAME]);

            for ($i = 0; $i < count($parameters); $i++) {
                $parameter = explode('=', $parameters[$i]);

                if(count($parameter) > 1) {
                    echo strcasecmp(strtolower(trim($parameter[0])), trim(strtolower($name)));
                    if(strcasecmp(strtolower(trim($parameter[0])), trim(strtolower($name))) == 0) {
                        return $parameter[1];
                    }
                }
            }

Answer 1

You're missing break; in for loop !

Yes, it could be encoding issue because function strcasecmp() works with Unicode only. Multi-byte characters such as UTF-8 or UTF-16 cannot be compared with strcasecmp() .

Also, strcasecmp() is case-insensitive function so using strtolower() against its parameters doesn't change function's result (string "example" is same as "EXAMPLE"m "eXaMPlE", "ExamPlE", etc).

You should set default result value (like $res=false; ) to be sure that result is set after loop.

You should replace for loop block with foreach loop like this one bellow

  $parameters = explode('|', $_COOKIE[Cisco_Rewards::REWARDS_SETTINGS_COOKIE_NAME]);

  // this will handle result
  $res = false;

  foreach ($parameters as $value) {
    $param = explode('=', $value);
    if(count($parameter) > 1) {
      // I guess this line is just for testing result
      echo "param1=".trim($param[0])."; param2=".trim($name)."; Result=".strcasecmp(trim($param[0]), trim($name)) . "<br />\n";

      if(strcasecmp(trim($param[0]), trim($name))) {
        $res=$param[1];
        // you should break here
        break;
        }
      }
    }
  // try to output result before (testing purpose only)
  var_dump($res);

  return $res;

But to make this solution easy you can use this function

  function getParamValue($parameters, $key) {
    $res = false;
    $plist = explode('|', $parameters);
    foreach ($plist as $pair) {
      $element = explode('=', $pair);
      if (trim($element[0]) == trim($key)) {
        $res = trim($element[1]);
        break;
        }
      }
    return $res;
    }

So if you have $parameters string like "console=1|userid=8159" and want to find value for $key string "userid" , put it into this function and it will return your result or false if $key was not found in $parameters list.

Example

  $parameters = "console=1|userid=8159";
  $name = "userid";

  echo getParamValue($parameters, $name);

Output

8159

Now you can write your code this way

$parameters = explode('|', $_COOKIE[Cisco_Rewards::REWARDS_SETTINGS_COOKIE_NAME]);
$value = getParamValue($parameters, $name);

And $value takes your result or returns false if $name is not in $parameters list.