how to check input .indexOf for multiple characters?

Question

I am trying to check if the user enters at least one number. If yes, the output = 'okey' else 'no number'. This works only for the first number, however when I enter 2, the function answers 'no number'. Any ideas? thanks!

        var firstName = document.getElementById('firstName');
        var alert = document.getElementById('check');

        function nameSecurityCheck() {
            var firstNameValue = firstName.value;
            if (firstNameValue.indexOf('1' || '2') === -1) {
                alert.textContent = 'no number';
            } else {
                alert.textContent = 'okey';
            }
        }
        firstName.addEventListener('blur', nameSecurityCheck, false);

score 3 · Accepted Answer · answered Nov 16 '15 at 23:27

3

Your problem is that you only check the indexOf for '1':

In particular, this statement:

'1' || '2' === '1'

Always evaluates to '1'. This means that your indexOf always checks for '1', never '2'.

You may be looking for this:

function nameSecurityCheck() {
        var firstNameValue = firstName.value;
        if (firstNameValue.indexOf('1') === -1 &&
            firstNameValue.indexOf('2') === -1) {
            alert.textContent = 'no number';
        } else {
            alert.textContent = 'okey';
        }
    }

Edit: However, since it looks like you're actually trying to check that a string contains a number, you can use a quick regex match for that:

var matches = value.match(/\d+/g);
if (matches == null) {
    alert('no number');
}

answered Nov 16 '15 at 23:27

TbWill4321

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25

You've covered everything I was trying to say with a bit more detail :) – Krease Nov 16 '15 at 23:33
thank you! what if I want to check if there is a capital letter? – mad.mix Nov 16 '15 at 23:40
Since that's a separate question, try searching it on SO first, it should be somewhere around here – TbWill4321 Nov 17 '15 at 00:20

how to check input .indexOf for multiple characters?

1 Answers1