PHP judge input does not exceed the length range of the MySQL varchar field _php tips

But if the Utf-8 code, a Chinese character is 3 characters long, such as String $str= "Hello!!";

If you use the Strlen function to determine that the length is 11, just over the length of the varchar, but actually it is not so, if you directly to the phpMyAdmin to execute the INSERT statement, this string can be inserted!

For a database, its length is 5, so how do we use PHP to get that length? Use the Iconv_strlen () function!

Echo Iconv_strlen ($str, ' utf-8′);

Note that the second argument is the current character set, so that the results you get from a different character set are calculated based on a character's length!

The above statement, will output 5, how would you judge it?