JavaScript limit string word wrap with bug

function Chang (str, len) {function Lenstat (str) {function Ischinese (str) {///judgment Yes                Not chinese var reCh =/[u00-uff]/;            return!rech.test (str); } var strlen = 0;                The initial definition length is 0 var text = Str.trim (); for (var i = 0; I<text. length; i++) {if (Ischinese (Text.charat (i))== true) {strlen= strlen+ 2;//Chinese is 2 characters} else {strlen= strlen+ 1;//English one character}}            return strlen; } var strlen= Lenstat (str); Console.log (strlen); var STRs= "; For (var i= 0;I <strlen; i= i+len) {STRs += str.substring (i,i + len) + "<br>";         } return STRs;             } chang (str,20);            Console.log (Chang (str,20));            var sd = document.getElementById (' SD '); Sd.innerhtml =chang (str,20);

The effect is as follows:

Bug problem:

are Chinese characters and character numbers counted as a truncated length? Instead of by character?

There are spaces in the middle that cannot be ignored.

JavaScript limit string word wrap with bug