UTF8 字节统计
1 function length4UTF8String(s) { 2 var total = 0; 3 var charCode = null; 4 for (var i = 0, len = s.length; i < len; i++) { 5 charCode = s.charCodeAt(i); 6 if (charCode <= 0x007f) { 7 total += 1; 8 } else if (charCode <= 0x07ff) { 9 total += 2; 10 } else if (charCode <= 0xffff) { 11 total += 3; 12 } else { 13 total += 4; 14 } 15 } 16 return total; 17 }