12 Common JS Regular Expressions _ Regular expressions

In this article, I've written 12 very useful regular expressions, which is a favorite of web developers.

1. In the input box can only enter the amount, in fact, can only enter a maximum of two decimal digits

The first type in the input box restricts 
 <input type= "text" maxlength= "8" class= "Form-control" id= "Amount" style= "margin-right:2px". Value= "" onchange= "count ();" onkeyup= "if (this.value==this.value2) return; if (This.value.search/^\d* (?: \. \d{0,2}) $/) ==-1) this.value= (this.value2) this.value2: "; else this.value2=this.value;" > 
//The second way to add dynamic forms to a form is only validated in the JS method. 
 var amount=$ ("#amount"). Val (); 
 if (Amount.search/^\d* (?: \. \d{0,2}) ($/) ==-1) { 
   alert ("The amount is not formatted, up to two decimal places"); 
   return false; 

2. Verify the mailbox format

var reg=/\w+ ([-+.] \w+) *@\w+ ([-.] \w+) *\.\w+ ([-.] \w+) * * *; 
 var email=$ ("#email"). Val (); 
 if (!reg.test (email)) { 
    alert ("Please enter the mailbox account that complies with the specification!") "); 
    return false; 
   } 

3. The password uses the numeral, the letter, the special character and the length is 8-20 bits

function Validatepwd (str) { 
if (/^.*?[ \d]+.*$/.test (str) &&/^.*? [A-za-z]/.test (str) 
&&/^.*?[ ~/'!@#$%^&* () _+| {}?;:><\-\]\\[\/].*$/.test (str) &&/^. {8,20}$/.test (str)) {return 
true; 
} 
return false; 
} 

4. Verify Telephone number

/** 
 * Verify phone number * 
 @param phonevalue number to verify 
 * @returns match returns True mismatch return false/ 
function Validatephone (phonevalue) { 
 phonevalue = Valuetrim (phonevalue); 
 var reg =/^[1][0-9]{10}$/; 
 Return Reg.test (Phonevalue); 
} 

5. Judge whether it is Chinese characters

/** 
 * Judge whether it is Chinese characters 
 * 
 * @param charvalue 
 *   to validate the data 
 * @returns match returns true mismatch return 
 false 
* * * function Ischaracter (charvalue) { 
 var reg =/^[\u4e00-\u9fa5]{0,}$/; 
 Return Reg.test (charvalue); 
} 

6. Is the letter: true: Yes, false: No

function Ischar (charvalue) { 
 var charpattern=/^[a-za-z]*$/;//is the letter 
 result=charpattern.test (charvalue); 
 return result; 
} 

7. Determining whether a number

function Isnum (numvalue) { 
 var numpattern=/^\d*$/;//number Regular expression 
 result=numpattern.test (NumValue); 
 return result; 
} 

8. The regular expression of an integer

function Isint (intvalue) { 
  var intpattern=/^0$|^[1-9]\d*$/;//integer Regular expression 
 result=intpattern.test (intvalue); 
  return result; 
 } 

9. Letters and Numbers

 function Ischarnum (flagvalue) { 
 var flagpattern=/^[a-za-z0-9]*$/;//is a letter and number 
 result=flagpattern.test ( Flagvalue); 
 return result; 
} 

10. Test 18 ID Number

/** 
 * Test 18 ID Number (15 digits can only detect the birthday is correct, to solve themselves) 
 * * 
 @param idcardvalue 
 *   18 ID Card number 
 * @returns Match return True mismatch return false 
/function idcardvildate (CID) { 
var arrexp = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5 , 8, 4, 2];//weighted factor 
var arrvalid = [1, 0, "X", 9, 8, 7, 6, 5, 4, 3, 2];//check code 
var reg =/^[1-9]\d{5}[1-9]\d{3} ((0\d) | (1[0-2]) ([[0|1|2]\d) |3[0-1]) \d{3} ([0-9]| X) $/; 
if (Reg.test (CID)) { 
var sum = 0, idx; 
for (var i = 0; i < cid.length-1 i++) { 
//pair of first 17 digits with weight product sum 
sum + = parseint (Cid.substr (i, 1), ten) * arrexp[i ]; 
} 
Computational modulus (fixed algorithm) 
idx = sum%; 
Check whether the 18th is equal to check code return 
Arrvalid[idx] = = CID.SUBSTR (1). toUpperCase (); 
else {return 
false; 
} 
} 

11. Verify that the birthday in the 15-digit ID number is a valid birthday

function Isvaliditybrithby15idcard (idCard15) { 
 var year = idcard15.substring (6, 8); 
 var month = idcard15.substring (8); 
 var day = idcard15.substring (a); 
 var temp_date = new Date (year, parsefloat (month)-1, parsefloat (day)); 
 The age of your old ID card does not need to consider the millennium bug problem and use the getyear () method 
 if (Temp_date.getyear ()!= parsefloat (year) 
   | | temp_date.getmonth ()! = parsefloat (month)-1 
   | | | temp_date.getdate ()!= parsefloat (day) {return 
  false; 
 } else {return 
  true ; 
 } 

12. Verify that the birthday in the 18-digit ID number is a valid birthday

function Isvaliditybrithby18idcard (idCard18) { 
 var year = idcard18.substring (6); 
 var month = idcard18.substring (a); 
 var day = idcard18.substring (a); 
 var temp_date = new Date (year, parsefloat (month)-1, parsefloat (day)); 
 Here use getFullYear () to get the year to avoid the bug problem 
 if (temp_date.getfullyear ()!= parsefloat () 
   | | temp_date.getmonth ()!= Parsefloat (month)-1 
   | | | temp_date.getdate ()!= parsefloat (day)) {return 
  false; 
 } else {return 
  true; 
 } 
}

This is the small collation of the web development commonly used in the form of validation of the regular expression, I hope you like.