验证始终无法验证

Question

Tried to add in some validation to a form, but it keeps acting as if the data that is being validated is invalid, even if its valid!

if (document.getElementById("mileageNumber").value  == /^[0-9]+$/)
{
    if (document.getElementById("vehicleNumber").value  == /^[0-9]+$/)
    {
        <Desired Action>
    }
    else
    {
        alert("Please Enter Numbers Only");
    }
}
else
{
    alert("Please Enter Numbers Only");
}

Can anybody see what i have done wrong?

Answer 1

You need to use the RegExp.test method.

/^[0-9]+$/.test(document.getElementById("mileageNumber").value);

You can also simplify your regular expression like so: /^\\d+$/

Answer 2

You'll need to test the regex and not evaluate it as a value.

if(/^[0-9]+$/.test(document.getElementById("vehicleNumber").value)){

    //Validation passed

}

Answer 3

You are comparing a string with a regex object. A regex object describes a structure of a regex object. A string is just a bunch of characters. They are simply not the same thing... ever. Just like the pseudo-code apples == carrots will never return true, string == regex will never return either. It requires a function to test if a string has the structure that the regex object describes.

You can properly test a string against a regex using string.match( .. ) .

document.getElementById("vehicleNumber").value.match( /^[0-9]+$/ );