JavaScript 小代码

JavaScript 前补“0”操作 

1. [代码]传统代码   

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/**  * 前补0操作  * @param number String 待操作字符串  * @param length int 目标长度  */ function addZero(number, length) {     var buffer = "";     if (number ==  "") {         for (var i = 0; i < length; i ++) {             buffer += "0";         }     } else {         if (length < number.length) {             return "";         } else if (length == number.length) {             return number;         } else {             for (var i = 0; i < (length - number.length); i ++) {                 buffer += "0";             }             buffer += number;         }     }     return buffer; }

2. [代码]这个代码更简洁     

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function addZero(str,length){                   return new Array(length - str.length + 1).join("0") + str;              }

 

JavaScript 根据长度截取字符串，超长部分追加...

1. [代码]js代码

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/**  * 根据长度截取先使用字符串，超长部分追加...  * @param str 对象字符串  * @param len 目标字节长度  * @return 处理结果字符串  */ function cutString(str, len) {     //length属性读出来的汉字长度为1     if(str.length*2 <= len) {         return str;     }     var strlen = 0;     var s = "";     for(var i = 0;i < str.length; i++) {         s = s + str.charAt(i);         if (str.charCodeAt(i) > 128) {             strlen = strlen + 2;             if(strlen >= len){                 return s.substring(0,s.length-1) + "...";             }         } else {             strlen = strlen + 1;             if(strlen >= len){                 return s.substring(0,s.length-2) + "...";             }         }     }     return s; }