JavaScript 小代碼

JavaScript 前補「0」操做 

1. [代碼]傳統代碼   

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/**   * 前補0操做   * @param number String 待操做字符串   * @param length int 目標長度   */ 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. [代碼]這個代碼更簡潔     

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

 

JavaScript 根據長度截取字符串，超長部分追加...

1. [代碼]js代碼

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/**   * 根據長度截取先使用字符串，超長部分追加...   * @param str 對象字符串   * @param len 目標字節長度   * @return 處理結果字符串   */ function cutString(str, len) {      //length屬性讀出來的漢字長度爲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; }