JS Regular Form Verification Summary, email verification, date validation, phone number verification, URL verification, credit card verification, QQ verification

This article summarizes a variety of regular verification, many are reproduced, I will try to verify the accuracy, if there are errors welcome message

The trim () method is incompatible in some browsers and it is best to rewrite the   string.prototype.trim=function () {           return This.replace (/(^\s*) | ( \s*$)/g, "");        }

Determines whether the input content is null    function IsNull () {        var str = document.getElementById (' str '). Value.trim ();        if (str.length==0) {            alert (' Sorry, the text box cannot be empty or is a space! '); /Please change the text box to the name of the property you need to verify!}    

Determines whether the date type is of type YYYY-MM-DD format    function IsDate () {         var str = document.getElementById (' str '). Value.trim ();        if (str.length!=0) {            var reg =/^ (\d{1,4}) (-|\/) (\d{1,2}) \2 (\d{1,2}) $/;     
        var reg =/^ (18|19|20) \d{2} (-|\/) (\d{1,2}) \2 (\d{1,2}) &/g;  You can use this method        var r = Str.match (reg)             to verify the exact point of the year. if (r==null)                alert (' Sorry, you have entered an incorrect date format! ');//Please change the "date" to the name of the property you need to verify!}         

Determines whether the date type is YYYY-MM-DD hh:mm:ss format type    function Isdatetime () {         var str = document.getElementById (' str '). Value.trim ();        if (str.length!=0) {              var reg =/^ (18|19|20) \d{2} (-|\/) (\d{1,2}) \2 (\d{2}) (\d{1,2}):(\d{1,2}):(\d{1,2}) $/g;          var r = Str.match (reg);             if (r==null)            alert (' Sorry, you have entered an incorrect date format! ');//Please change the "date" to the name of the property you need to verify!}         

JS Regular Form Verification Summary, mailbox verification, date validation, phone number verification, URL verification, credit card verification, QQ authentication