js字符限制(字符截取) 一个中文汉字算两个字符

html &lt;input type="text" id="txt"&gt; 核心js代码 //字符串截取 function getByteVal&#40;val, max&#41; { var returnValue = ''; var byteValLen = 0; for (var i = 0; i < val xss=removed xss=removed xss=removed> max) break; return