Regex.match returns null

[user1980]

hi there

it seems to be simple but i do not know why my java script function does not work.

function validatePartialDateInput(SourceField, FieldLabel) {
   
        var sField = document.getElementById('ctl00_ContentPlaceHolder1_'+ SourceField);
             
        var regex_dt = '/^\d{1,2}[/]\d{4}$/';
        alert((sField.value));
        alert(regex_dt.match(sField.value));//returns null
        if(sField.value.length > 0)
        { 
        if (regex_dt.match(sField.value))
        { 
        alert(sField.value);
            alert(FieldLabel);
        }
        }
    }

the regex.match returns null....I have no clue why....can somebody please throw some light on this..thank you

[Rabbit]

You haven't created a regex object. All you have there is a string.

[user1980]

thank you..i thought if it is java script I don't have to create a object.
anyways, when I created the object it worked...

    var regex_dt = new RegExp('/^\d{1,2}[/]\d{1,4}$/',"");

however, my regex always returns false..

function validatePartialDateInput(SourceField, FieldLabel) {
   
        var sField = document.getElementById('ctl00_ContentPlaceHolder1_'+ SourceField);
             
        var regex_dt = new RegExp('/^(0[1-9]|1[012])[- /.](19|20)\d\d$/',"");
        alert((sField.value));
        alert(regex_dt.test(sField.value));//always returns false
        if(sField.value.length > 0)
        { 
        if (!regex_dt.test(sField.value))
        { 
            alert(FieldLabel);
        }
        }
    }

i have changed my regex to , '/^(0[1-9]|1[012])[- /.](19|20)\d\d$/' to validate mm/yyyy. it always returns false....thank you

[Rabbit]

If you use RegExp to create your regular expression, you don't use the regular expression delineators. And if you're using RegExp, you need to escape all forward slashes.
var regex_dt = new RegExp('(0[1-9]|1[012])[- /.](19|20)\\d\\d', "");

[user1980]

thank you for the reply but still no use....

[Rabbit]

I missed the closing quote on the regex string. Put that back in and it should work.

[user1980]

I do have the closing quote...anyways , this is what i have now...

function validatePartialDateInput(SourceField, FieldLabel) {
   
        var sField = document.getElementById('ctl00_ContentPlaceHolder1_'+ SourceField);
             
        var regex_dt = new RegExp('^(0[1-9]|1[012])[- /.](19|20)\d\d$',"");
        alert((sField.value));
        alert(regex_dt.test(sField.value));
        if(sField.value.length > 0)
        { 
        if (!regex_dt.test(sField.value))
        { 
           alert(FieldLabel);
        }
        }
    }

[Rabbit]

That's not even what I have in my code. Look again at my post.

[user1980]

I have not taken a closer look at the expression..now it works..thank you....