javascript中各种正则表达式验证

 /*验证email*/  
   var str=email;
   var expression = /\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;  
   var objExp = new RegExp(expression);  
   if(objExp.test(str) == true){  
        return true ;   
    }else
        return false;

  
 /*验证电话号码*/ 
   var str=tel;
   var expression=/(\d{3}-?\d{8}|(\d{4}-)(\d{7})/;  
   var objExp = new RegExp(expression); 
   if(objExp.test(str) == true){  
       return true ;   
   }else
       return false;


 /*验证是否是汉字*/
   var str=name;
   var expression = /[\u4E00-\u9FA5/;  
   var objExp = new RegExp(expression); 
   if(objExp.test(str) == true){  
       return true ;   
   }else
       return false; 


 /*验证身份证号码*/
   var str=NO;
   var expression = /\d{17}[\d|X]|\d{15}/;  
   var objExp = new RegExp(expression); 
   if(objExp.test(str) == true){  
       return true ;   
   }else
       return false; 


 /*验证网址是否合法*/
    var str=url;
    var expression = /http(s)?:\/\/([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?/;  
    var objExp = new RegExp(expression); 
    if(objExp.test(str) == true){  
        return true ;   
    }else
        return false; 


 /*限制字符串长度str为指定字符串，digit为指定最大长度*/  
 function checkstr(str,digit)
 {
    var n=0;
    for(int i=0;i<str.length;i++)
    {
       var leg=str.charCodeAt(i);
       if(leg>255)
       {
          n+=2;
       }else
          n+=1;
    }
    if(n>digit)
    {
        return true;
    }else
        return false;
 }