string帮助类

package com.hacker{    
         
     
    public class StringUtil{    
                     
         //忽略大小字母比较字符是否相等;    
         public static function equalsIgnoreCase(char1:String,char2:String):Boolean{    
             return char1.toLowerCase() == char2.toLowerCase();    
         }    
             
         //比较字符是否相等;    
         public static function equals(char1:String,char2:String):Boolean{    
             return char1 == char2;    
         }    
             
         //是否为Email地址;    
         public static function isEmail(char:String):Boolean{    
             if(char == null){    
                 return false;    
             }    
              char = trim(char);    
               var pattern:RegExp = /(\w|[_.\-])+@((\w|-)+\.)+\w{2,4}+/;     
               var result:Object = pattern.exec(char);    
              if(result == null) {    
                   return false;    
               }    
               return true;    
           }    
               
           //是否是数值字符串;    
           public static function isNumber(char:String):Boolean{    
               if(char == null){    
                 return false;    
               }    
               return !(isNaN(Number(char)))    
           }    
               
          //是否为Double型数据;    
           public static function isDouble(char:String):Boolean{    
               char = trim(char);    
               var pattern:RegExp = /^[-\+]?\d+(\.\d+)?$/;     
              var result:Object = pattern.exec(char);    
               if(result == null) {    
                   return false;    
               }    
               return true;    
          }    
           //Integer;    
           public static function isInteger(char:String):Boolean{    
               if(char == null){    
                   return false;    
               }    
              char = trim(char);    
              var pattern:RegExp = /^[-\+]?\d+$/;     
               var result:Object = pattern.exec(char);    
               if(result == null) {    
                 return false;    
               }    
               return true;    
          }    
          //English;    
           public static function isEnglish(char:String):Boolean{    
               if(char == null){    
                  return false;    
              }    
               char = trim(char);    
               var pattern:RegExp = /^[A-Za-z]+$/;     
               var result:Object = pattern.exec(char);    
              if(result == null) {    
                  return false;    
              }    
              return true;    
          }    
           //中文;    
           public static function isChinese(char:String):Boolean{    
              if(char == null){    
                  return false;    
              }    
              char = trim(char);    
               var pattern:RegExp = /^[\u0391-\uFFE5]+$/;     
              var result:Object = pattern.exec(char);    
              if(result == null) {    
                 return false;    
             }    
             return true;    
         }    
         //双字节    
           public static function isDoubleChar(char:String):Boolean{    
               if(char == null){    
                   return false;    
               }    
               char = trim(char);    
               var pattern:RegExp = /^[^\x00-\xff]+$/;     
               var result:Object = pattern.exec(char);    
               if(result == null) {    
                   return false;    
               }    
               return true;    
           }    
          //含有中文字符    
          public static function hasChineseChar(char:String):Boolean{    
              if(char == null){    
                  return false;    
              }    
              char = trim(char);    
              var pattern:RegExp = /[^\x00-\xff]/;     
              var result:Object = pattern.exec(char);    
              if(result == null) {    
                  return false;    
              }    
              return true;    
          }    
          //注册字符;    
          public static function hasAccountChar(char:String,len:uint=15):Boolean{    
              if(char == null){    
                  return false;    
              }    
              if(len < 10){    
                  len = 15;    
              }    
              char = trim(char);    
              var pattern:RegExp = new RegExp("^[a-zA-Z0-9][a-zA-Z0-9_-]{0,"+len+"}$", "");     
              var result:Object = pattern.exec(char);    
              if(result == null) {    
                  return false;    
              }    
              return true;    
          }    
          //URL地址;    
          public static function isURL(char:String):Boolean{    
              if(char == null){    
                  return false;    
              }    
              char = trim(char).toLowerCase();    
              var pattern:RegExp = /^http:\/\/[A-Za-z0-9]+\.[A-Za-z0-9]+[\/=\?%\-&_~`@[\]\':+!]*([^<>\"\"])*$/;     
              var result:Object = pattern.exec(char);    
              if(result == null) {    
                  return false;    
              }    
              return true;    
          }    
              
          // 是否为空白;            
          public static function isWhitespace(char:String):Boolean{    
              switch (char){    
                  case " ":    
                  case "\t":    
                  case "\r":    
                  case "\n":    
                  case "\f":    
                      return true;        
                  default:    
                      return false;    
              }    
          }    
              
          //去左右空格;    
          public static function trim(char:String):String{    
              if(char == null){    
                  return null;    
              }    
              return rtrim(ltrim(char));    
          }    
              
          //去左空格;     
          public static function ltrim(char:String):String{    
              if(char == null){    
                  return null;    
              }    
              var pattern:RegExp = /^\s*/;     
              return char.replace(pattern,"");    
          }    
              
          //去右空格;    
          public static function rtrim(char:String):String{    
              if(char == null){    
                  return null;    
              }    
              var pattern:RegExp = /\s*$/;     
              return char.replace(pattern,"");    
          }    
              
          //是否为前缀字符串;    
          public static function beginsWith(char:String, prefix:String):Boolean{                
              return (prefix == char.substring(0, prefix.length));    
          }    
              
          //是否为后缀字符串;    
          public static function endsWith(char:String, suffix:String):Boolean{    
              return (suffix == char.substring(char.length - suffix.length));    
          }    
              
          //去除指定字符串;    
          public static function remove(char:String,remove:String):String{    
              return replace(char,remove,"");    
          }    
              
          //字符串替换;    
          public static function replace(char:String, replace:String, replaceWith:String):String{                
              return char.split(replace).join(replaceWith);    
          }    
              
          //utf16转utf8编码;    
          public static function utf16to8(char:String):String{    
              var out:Array = new Array();    
              var len:uint = char.length;    
              for(var i:uint=0;i<len;i++){    
                  var c:int = char.charCodeAt(i);    
                  if(c >= 0x0001 && c <= 0x007F){    
                      out[i] = char.charAt(i);    
                  } else if (c > 0x07FF) {    
                      out[i] = String.fromCharCode(0xE0 | ((c >> 12) & 0x0F),    
                                                   0x80 | ((c >>  6) & 0x3F),    
                                                   0x80 | ((c >>  0) & 0x3F));    
                  } else {    
                      out[i] = String.fromCharCode(0xC0 | ((c >>  6) & 0x1F),    
                                                   0x80 | ((c >>  0) & 0x3F));    
                  }    
              }    
              return out.join('');    
          }    
              
          //utf8转utf16编码;    
          public static function utf8to16(char:String):String{    
              var out:Array = new Array();    
              var len:uint = char.length;    
              var i:uint = 0;    
              while(i<len){    
                  var c:int = char.charCodeAt(i++);    
                  switch(c >> 4){    
                      case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:    
                          // 0xxxxxxx    
                          out[out.length] = char.charAt(i-1);    
                          break;    
                      case 12: case 13:    
                          // 110x xxxx   10xx xxxx    
                          var char2:int = char.charCodeAt(i++);    
                          out[out.length] = String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));    
                          break;    
                      case 14:    
                          // 1110 xxxx  10xx xxxx  10xx xxxx    
                          var char2:int = char.charCodeAt(i++);    
                          var char3:int = char.charCodeAt(i++);    
                          out[out.length] = String.fromCharCode(((c & 0x0F) << 12) |    
                              ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));    
                          break;    
                  }    
              }    
              return out.join('');    
          }    
              
              
          function StringUtil(){    
              throw new Error("StringUtil class is static container only");    
          }    
      }    
  }


来自：hacker