How to check if a string contains a certain Chinese word in PHP?

Question

I got a string $str = "颜色代码";, I would like to check if this string contain "颜色". I've tried using the code below, but I keep getting false return.

mb_strpos($str, "颜色", 0 ,"GBK");

Answer 1

Maybe you just have forgotten to check whether the value is integer:

if(mb_strpos($str, "颜色", 0 ,"GBK")===false)
    echo "The value does not contain \"颜色\"\n";
else
    echo "\"颜色\" is part of the string."

The three = invoke a strict type comparison. Normally, false equals 0, but they are of different variable types - bool and int respectively.

In the documentation of strpos, which acts similarly, there's a big red warning:

Warning

This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

Answer 2

Try using utf8_decode:

mb_strpos($str, utf8_decode("颜色"), 0 ,"GBK");

Answer 3

The code does work:

$str = "颜色代码";
$test = mb_strpos($str, "颜色", 0 ,"GBK");
echo $test;

But the problem you are facing is because the 颜色 strpos returns 0 which is the correct string position but your code logic might misinterpret that as false. To see what I mean take the 颜色 and place it at the end of the string like this:

$str = "代码颜色";
$test = mb_strpos($str, "颜色", 0 ,"GBK");
echo $test;

And the returned string position is 3 which is correct as well. A better approach to simply see if the 颜色 is in the string is to use preg_match like this:

$str = "颜色代码";
$test = preg_match("/颜色/", $str);
echo $test;

And the output for that would be a boolean 1 which equates to true which I believe is what you are looking for.

Beyond the functionality working as expected, there is a clear speed benefit to using preg_match over mb_strpos as shown here.

mb_strpos: 3.7908554077148E-5
preg_match: 1.1920928955078E-5

It’s more than 3x faster to use preg_match when compared to mb_strpos.