GBK, UTF8 string actual length calculation function implemented by JavaScript_Basic knowledge

As we all know, the length of strings in JS does not distinguish between Chinese and English characters. Each character counts as a length, which is different from the strlen() function in PHP. The strlen() function in PHP accumulates GBK Chinese characters by 2 and UTF-8 Chinese characters by 3 according to the character set.

Some children’s shoes may ask, why do we need to calculate the actual length?

Mainly to match the length range of the database. For example, a field in GBK's database is varchar(10), which is equivalent to the length of 5 Chinese characters, and one Chinese character is equal to the length of two letters. If it is a UTF8 database, the length of each Chinese character is 3.

After knowing the above principles, we can calculate the actual length of a string. If it is a GBK character set, add 2 when encountering Chinese characters. If it is a UTF8 character set, add 3 when encountering Chinese characters.
GBK length calculation function:

Copy code The code is as follows:

// Actual length calculation of GBK character set
function getStrLeng(str){
var realLength = 0;
var len = str.length;
var charCode = -1;
for(var i = 0; i < len; i ){
​​​​ charCode = str.charCodeAt(i);
If (charCode >= 0 && charCode <= 128) {
                realLength = 1;
          }else{
                      // If it is Chinese, add 2 to the length
               realLength = 2;
        }
}  
Return realLength;
}

UTF8 length calculation function:

Copy code The code is as follows:

// UTF8 character set actual length calculation
function getStrLeng(str){
var realLength = 0;
var len = str.length;
var charCode = -1;
for(var i = 0; i < len; i ){
​​​​ charCode = str.charCodeAt(i);
If (charCode >= 0 && charCode <= 128) {
                realLength = 1;
          }else{
                     // If it is Chinese, add 3 to the length
               realLength = 3;
        }
}  
Return realLength;
}