Check letters from array jquery

Question

I have an example code which checks that which user types in the input are available in the javascript array.

var postcodes = ["00-240", "80", "32", "90", "91"];
$('#test').keyup(function () {
    var val = this.value; 
    var m = $.map(postcodes, function (value, index) {
        var reg = new RegExp('^' + val + '.*$');
        return value.match(reg);
    });
    $('#msg').text(m.length && val.length ? 'VALID' : 'INVALID');
});

I want to set VALID also when user type: 80-215, 80-512, 32-125 etc. Now if i type 80 or 32 it's display valid but when I write 80-215 or 32-111 it will show invalid. I want to check that some string from the array is available in string which is request from user (with emphasis on the order of letters).

I will be gratefull for any tips.

Regards

Your code needs to go in the question. You can't just dump a jsbin/jsfiddle link on us an expect us to debug it for you; your question needs to be self-contained and answerable without opening any external links. — user229044, Aug 07 '14 at 16:49

score 0 · Answer 1 · edited May 23 '17 at 11:57

You have some problems:

You must escape special regex characters when you build a regex from an untrusted string.
Since you want to match strings starting with codes in the array, you must build regular expressions from each array entry, not user input
To test if there are some matches, better use Array.prototype.some than Array.prototype.map
Text fields can change by other ways than keyboard, e.g. pasting with mouse. Better listen to input event instead of keyup one.

var postCodes = ["00-240", "80", "32", "90", "91"],
    postRegExp = postCodes.map(function(code) {
        return new RegExp('^' + code.replace(/[.^$*+?()[{\\|]/g, '\\$&'));
    });
document.getElementById('test').oninput = function () {
    var val = this.value,
        m = postRegExp.some(function(regExp){
            return regExp.test(val);
        });
    document.getElementById('msg').innerHTML = m ? 'VALID' : 'INVALID';
};

However, instead of regex, you could try ES6 String.prototype.startsWith:

var postCodes = ["00-240", "80", "32", "90", "91"];
document.getElementById('test').oninput = function () {
    var val = this.value,
        m = postCodes.some(code => val.startsWith(code));
    document.getElementById('msg').innerHTML = m ? 'VALID' : 'INVALID';
};

Check letters from array jquery

1 Answers1