Question

I am trying to test passwords. I need to do some testing on the string. I am finding that my special characters evaluate to true when I test them with toUpperCase(). I would suspect that they would evaluate to false.

How should I test for special characters?

// CREATE ARRAY OF CHARACTERS
CharacterArray = ["1","2","3","a","b","c","D","E","F","/","+",")"];

// TEST CHARACTERS 
function testCharacters() {
    // GET ARRAY LEN
    var CharacterArrayLen = CharacterArray.length;
    // LOOP THROUGH ARRAY
    for (i = 0; i < CharacterArrayLen; i++) {
        // PARSE SINGLE CHARACTER
        var ThisChar = CharacterArray[i];

        if (!isNaN(ThisChar)) {
            alert(ThisChar + ' is numeric!');
        } else {
            if (ThisChar === ThisChar.toUpperCase()) {
                alert(ThisChar + ' is upper case');
            } else if (ThisChar === ThisChar.toLowerCase()) {
                alert(ThisChar + " is lower case");
            }
        }   
    }
}
testCharacters();

Answer 1

They aren’t upper or lower case. Both toUpperCase and toLowerCase return the same thing for those characters. If you tested for lower case first, you’d find they’re all lower case!

You can use some regex to see if the character is in the alphabet.

ThisChar.match(/^[a-zA-Z]$/)

will return null on non-alphabet characters.

If you’re just trying to see if each of those characters is in your array, you can use indexOf

CharacterArray.indexOf('a')
> 3
CharacterArray.indexOf('A')
> -1

The second one returns -1 because A is not in the array.

Here’s a DEMO using regex.