jQuery: Check if special characters exists in stri

Question

I know this question is asked more often here on Stack, but I can't seem to get a straight answer out of the questions already posted.

I need to check if all special characters (except -) are in a string, if so, then give the user an alert.

What I have so far is this:

if($('#Search').val().indexOf('@') == -1 || $('#Search').val().indexOf('#') == -1 || $('#Search').val().indexOf('$') == -1 || $('#Search').val().indexOf('%') == -1 || $('#Search').val().indexOf('^') == -1 || $('#Search').val().indexOf('&') == -1 || $('#Search').val().indexOf('*') == -1 || $('#Search').val().indexOf('(') == -1 || $('#Search').val().indexOf(')') == -1 || $('#Search').val().indexOf('_') == -1 || $('#Search').val().indexOf('\'') == -1 || $('#Search').val().indexOf('\"') == -1 || $('#Search').val().indexOf('\\') == -1 || $('#Search').val().indexOf('|') == -1 || $('#Search').val().indexOf('?') == -1 || $('#Search').val().indexOf('/') == -1 || $('#Search').val().indexOf(':') == -1 || $('#Search').val().indexOf(';') == -1 || $('#Search').val().indexOf('!') == -1 || $('#Search').val().indexOf('~') == -1 || $('#Search').val().indexOf('`') == -1 || $('#Search').val().indexOf(',') == -1 || $('#Search').val().indexOf('.') == -1 || $('#Search').val().indexOf('<') == -1 || $('#Search').val().indexOf('>') == -1 || $('#Search').val().indexOf('{') == -1 || $('#Search').val().indexOf('}') == -1 || $('#Search').val().indexOf('[') == -1 || $('#Search').val().indexOf(']') == -1 || $('#Search').val().indexOf('+') == -1 || $('#Search').val().indexOf('=') == -1)
{
   // Code that needs to execute when none of the above is in the string
}
else
{
  alert('Your search string contains illegal characters.');
}

But this doesn't seem to work... Can anyone help me on this matter?

Thanks in advance!

Guido

Answer 1

var specialChars = "<>@!#$%^&*()_+[]{}?:;|'\"\\,./~`-="
var check = function(string){
    for(i = 0; i < specialChars.length;i++){
        if(string.indexOf(specialChars[i]) > -1){
            return true
        }
    }
    return false;
}

if(check($('#Search').val()) == false){
    // Code that needs to execute when none of the above is in the string
}else{
    alert('Your search string contains illegal characters.');
}

Answer 2

You are checking whether the string contains all illegal characters. Change the ||s to &&s.

Answer 3

You could also use the whitelist method -

var str = $('#Search').val();
var regex = /[^\w\s]/gi;

if(regex.test(str) == true) {
    alert('Your search string contains illegal characters.');
}

The regex in this example is digits, word characters, underscores (\w) and whitespace (\s). The caret (^) indicates that we are to look for everything that is not in our regex, so look for things that are not word characters, underscores, digits and whitespace.

Answer 4

If you really want to check for all those special characters, it's easier to use a regular expression:

var str = $('#Search').val();
if(/^[a-zA-Z0-9- ]*$/.test(str) == false) {
    alert('Your search string contains illegal characters.');
}

The above will only allow strings consisting entirely of characters on the ranges a-z, A-Z, 0-9, plus the hyphen an space characters. A string containing any other character will cause the alert.