Run javascript block just once

Question

I have this javascript function and I want to alert 12, 24, 36 ... and so on in the multiples of 12 . I have attached the code below

<script type="text/javascript">
    function test() {
        var global1=12;
        var final;
        var check;
        if(check) {
            final=global1;
            check=true;
        } else {
            final=final+12;
        }
        alert(final);
    }

    test();
    test();
    test();
</script>

You code does not make much sense; you only set `check` when it is `true` (never...) and all your variables are local: https://stackoverflow.com/questions/500431/what-is-the-scope-of-variables-in-javascript — jeroen, Feb 09 '18 at 12:42
Apart from that you have failed to tell us what the problem is and what you want to achieve exactly. — jeroen, Feb 09 '18 at 12:43

score 1 · Accepted Answer · answered Feb 09 '18 at 12:46

1

You could take a closure over the value and the final value and return a function for updating the value until it reaches the final value.

var test = function (final) {
        var value = 0;
        return function () {
            if (value < final) {
                value += 12;
            }
            console.log(value);
        };
    }(36); // call with final value

test();
test();
test();
test();

answered Feb 09 '18 at 12:46

Nina Scholz

376,160
25
347
392

Looking at the OP's original code, this might be a bit too much :-) – jeroen Feb 09 '18 at 12:49
@jeroen, it is just another approach without using global to tackle that problem. this answer is just an offer, if op like to have some more tools. – Nina Scholz Feb 09 '18 at 12:52
To be clear, I was referring to the OP's programming skills, not your solution. – jeroen Feb 09 '18 at 12:57

score 0 · Answer 2 · answered Feb 09 '18 at 12:43

0

In addition to my comment, here is a much simpler version for your function :

var count = 0;

function twelve(){
  count += 12;
  console.log(count);
}

twelve();
twelve();
twelve();

answered Feb 09 '18 at 12:43

Zenoo

12,670
4
45
69

MH2K9 · Answer 3 · 2018-02-09T12:48:35.330

0

Declare the variables globally instead of function block. Example:

var global1 = 12;
var final;
var check = true;

function test()
{
    if(check) {
        final = global1;
        check = false;
    } else {
        final = final + 12;
    }
    alert(final);
}

test();
test();
test();

edited Feb 09 '18 at 12:48

answered Feb 09 '18 at 12:44

MH2K9

11,951
7
32
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Run javascript block just once

3 Answers3