Question

78

How to validate a text string using javascript?

rated 0 times [ 81] [ 3] / answers: 1 / hits: 14756 / 11 Years ago, fri, december 13, 2013, 12:00:00

So I want to create a prompt that asks for a clients name. I want to make sure it is formatted in this way: Last name, first name, middle initial and no name longer than 20 characters.
Here is what I have so far, but not sure where to go from here.

<script language=JavaScript>

//Get the name

var name = prompt(What is your Name?);



//validate

if(name)

//output

document.write (That is your name! :));



else

document.write (Please use the format Last name, first name, middle initial);

 </script>

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gavenmekhio

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4 Years ago

answered 11 Years ago jimmieo · Accepted Answer

Have a look at the below simple steps using regular expression :

// Get name

var name = prompt(What is your Name?);



// match name with regular expression

if (name.match(^[A-Za-z]{1,20}, [A-Za-z]{1,20}, [A-Za-z]{1,20})) {

    document.write(That is your name! :));

} else {

    document.write(Please use the format Last name, first name, middle initial);

}

Result :

Match :

abc, xyz, m ,

abcabcabc, xyzzyz, mr

Non Matchs :

, xyz, m ,

123, a, b,

iammorethantwentycharactersfirstname, middle, initial