Question

I’m not sure if this is even what you call it, but basically, I am grabbing a list of cities that is stored in one key in local storage. I am splitting them by comma, and then dynamically checking the checkboxes with the corresponding values for the id. Now I want to have any number of cities in there so I don’t want to check the boxes individually like [0], [1] etc but is there there like a unlimited way to do this or something. Sorry if this isn’t clear..Ill post my code below, My code below is checking the boxes from keys 0-5, I want to be able to do 0 – unlimited , so to speak. Any help is appreciated.

<script type="text/javascript">
            var refreshId = setInterval(function()
                                        {
            var citySplit = localStorage.getItem("city2");

            var myResult = citySplit.split(",");

            $("#"+myResult[0]+"").prop("checked", true);
            $("#"+myResult[1]+"").prop("checked", true);
            $("#"+myResult[2]+"").prop("checked", true);
            $("#"+myResult[3]+"").prop("checked", true);
            $("#"+myResult[4]+"").prop("checked", true);
            $("#"+myResult[5]+"").prop("checked", true);
             }, 6500);

            </script>

Answer 1

Many ways to do this:

NOTE: All of these examples are untested.

---

Simple while-loop – 0, 1, 2, 3, 4

var i = 0,
    len = myResult.length;

while ( i < len ) {
    $( "#" + myResult[i] ).prop("checked", true);
    i++;
}

---

Simple for-loop – 0, 1, 2, 3, 4

for ( var i = 0, len = myResult.length; i < len; i++ ) {
    $( "#" + myResult[i] ).prop("checked", true);
}

---

jQuery.each method with callback using this

$.each(myResult, function() {
    $( "#" + this ).prop("checked", true);
}

or
jQuery.each method with callback using arguments[1] (value)

$.each(myResult, function(key, value) {
    $( "#" + value ).prop("checked", true);
}

---

while-loop from behind 4, 3, 2, 1, 0

var len = myResult.length

while( len-- ) {
    $( "#" + myResult[len] ).prop("checked", true);
}

---

for-loop from behind 4, 3, 2, 1, 0

for( var i = myResult.length; i > 0; i-- )
    $( "#" + myResult[i-1] ).prop("checked", true);

---

while-loop popping array This destroys the array from behind 4, 3, 2, 1, 0

while( myResult.length ) {
    $( "#" + myResult.pop() ).prop("checked", true);
}

or
while-loop shifting array This destroys the array from the start 0, 1, 2, 3, 4

while( myResult.length ) {
    $( "#" + myResult.shift() ).prop("checked", true);
}

---

???

---

$.map(myResult, function(value) {
    return "#" + value;
}).each(function() {
    $(this).prop("checked", true);
};

---

$.map(myResult, function( value ) {
    return $("#" + value);
}).prop("checked", true);

---

As you can see there is many ways to dealing with arrays.

For simple thing I will recommend you to use one of the two first methods.

The jQuery.each method is very nice because you get a the key and value of the array in a local scope. (key = 0, 1, 2, 3, 4, …) (value = what ever myResult[key] is).

The two where we destroy the array is also very nice. But I will not recommend you not to use these before you understand more simple methods. As situation i can think of using this method is if you have to load a lot of files or initialize a lot of functions in a specific order:

var func1 = function() {
        alert("func1");
    },
    func2 = function() {
        alert("func2");
    },
    func3 = function() {
        alert("func3");
    },
    queue = [func1, func2, func3];

while( queue.length ) {
    (queue.shift())(); 
    // or
    //(queue.pop())();
}