验证电话号码

Question

如何确定输入的家庭电话号码是否有效（没有区号）？

Answer 1

Regex is the best option for validating a phone number.

you can use it on the html input tag like this (this may not be supported in all browsers):

<input id="phonenum" type="tel" pattern="^\d{3}-\d{4}$" required > 

or you can test a regex string in you code like this (also, this is the correct format for you function above):

<script type="text/javascript">
     //function\\
     function validPhone(phoneNum) {
         var reg = new RegExp("^\d{3}-\d{4}$");
         if (reg.test(phoneNum)) {
             return "True";
         }
         else {
             return "False";
         }
     }
</script>

and if you want to make it short and sweet and you just need to return a bool value, you can do do this:

<script type="text/javascript">
     //function\\
     function validPhone(phoneNum) {
         var reg = new RegExp("^\d{3}-\d{4}$");
         return reg.test(phoneNum);
     }
</script>

Answer 2

You should only have parenthesis/brackets after an else if statement. Not an else statement.

Example: If(true){ }else if(true){ }

Or

If(true){
}else{
}

NOT if(true){ }else(){ }