Check is character is in array while typing

Question

I have a problem with my jQuery code.

I want to check characters from strings which is in array while user typing something in the input.

var postcodes = ["00-240","80","32","90","91"];

$('input[name="text-391"]').keyup(function(){
    var header = $('#postalcode').val();

    if($('input[name="text-391"]').val().length > 1) {
        if($.inArray(header, postcodes) > -1){
            alert("None");
        }
    }

This code checks that all what user type in the input is in array, but i want to check this letter after letter.

For example:

user types: 0 - it's ok

user types: 00 - it's still ok

user types 00-340 - it's not ok and now I want to display warning that we haven't it in the array

user types: 3 - it's ok

user types: 35 - it's not ok, and now i want to display warning that we haven't it in the array

I will be very grateful for any tips. Regards

Answer 1

You can use jQuery.map to return matched results as an array - then check the array size to see if they are good or not

var postcodes = ["00-240","80","32","90","91"];
$('#test').keyup(function(){
    var val = this.value;// get current value in textbox
    // use map to get all the ones that matches
    var m =  $.map(postcodes,function(value,index){
       // regex object to match on - must start with the current value
       var reg = new RegExp('^'+val+'.*$')
       // return values that matches the current value 
       return value.match(reg);
    });

    // display valid if input has at least one character
    // and if there is at lease 1 match 
    // (m.length will be 0 if there are no matches)
    // else display invalid
    $('#msg').text(m.length && val.length ? 'VALID':'INVALID');
});

EXAMPLE