How to use php to determine that the input does not exceed the length range of the varchar field of mysql

This article mainly introduces how to use PHP to determine the length range of the varchar field that the input does not exceed mysql. It has a certain reference value. Now I share it with you. Friends in need can refer to it

varchar Type field, if you set the length to 10, then 10 can be stored regardless of Chinese characters or English.

But if under utf-8 encoding, a Chinese character occupies 3 characters in length, such as the string $str=”Hello!!”;
If you use the strlen function to judge, The length is 11, which just exceeds the length of varchar, but in fact it is not the case. If you directly execute the insert statement in phpmyadmin, this string can be inserted!
For the database, its length is 5, so how do we use PHP to get this length? Use the iconv_strlen() function!

echo iconv_strlen($str,'utf-8′);

Note that the second parameter is the current character set, so the results you get according to different character sets are calculated based on the length of one character!
The above statement will output 5. How about it? Can you judge it?

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