Question

31

Javascript - increment value by 4.

rated 0 times [ 33] [ 2] / answers: 1 / hits: 16086 / 12 Years ago, wed, august 1, 2012, 12:00:00

I have a problem.

I need a Javascript function which increase (increment) variable value by 4, and when the variable value is 20, then set value of variable to 0 and again increment it by 4 and so on...

I think that I need for loop and if condition, but I don't know how to implement this...

Example

the result must be:

x = 0; then x = 4, x = 8, x = 12, x = 16, x = 20, x = 0, x= 4 ....

Thank you

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ramseydeshaunc

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1 Year ago

answered 12 Years ago agustindejonm · Accepted Answer

You can do this with a nested pair of loops:

while (true) {

    for (var x = 0; x <= 20; x += 4) {

        // use x

    }

}

This will be more efficient than using the mod (%) operator.

EDIT

From your comments, it sounds like you want to generate the sequence incrementally, rather than in a loop. Here's a function that will return a function that will generate the next element of your sequence each time you call it:

function makeSequence() {

    var x = 20; // so it wraps to 0 first time

    return function() {

        if (x == 20) { x = 0 }

        else { x += 4 }

        return x;

    }

}

You could then use it like this (among many ways):

var sequence = makeSequence();



// and each time you needed the next element of the sequence:



var x = sequence();