How to obtain the number of bytes of a string using JavaScript

The number of bytes of an English character is different from that of a Chinese character or Japanese character. If you directly use the Javascript Len function, the length of an English letter or Chinese character is considered to be 1. If the data needs to be stored in the database, the length cannot be effectively controlled, which may cause some risks. Two simple methods are used to calculate the length.

STR = escape ("Chinese ABC ,,");
Len = 0;
For (I = 0; I <Str. length; I ++, Len ++ ){
If (Str. charat (I) = "% "){
If (Str. charat (++ I) = "U "){
I + = 3;
Len ++;
}
I ++;
}
}
Alert (LEN );

STR = "Chinese characters ABC ,,";
Len = 0;
For (I = 0; I <Str. length; I ++ ){
Icode = Str. charcodeat (I );
If (icode> = 0 & icode <= 255) | (icode> = 0xff61 & icode <= 0xff9f )){
Len + = 1;
} Else {
Len + = 2;
}
}
Alert (LEN );