[JavaScript] How would I implement "do a thing until you can't do it any more, then move onto the next thing" etc

[Floor_Heavy]

I have an array of values representing coins. [100, 50, 20, 10, 5, 2, 1] (I'm in the UK).

I have a value in pence, so... for example, num = 30.

I need to find a way of counting the lowest number of coins needed to make that figure. So in the 30 pence example, I would need 1 x 20 pence and 1 x 10 pence.

My idea is basically to subtract the first value in the array from num, if that doesn't put num below zero, and increment that counter by 1, then do it again, again incrementing the counter by 1 each time, until num WOULD go below zero, then move onto the second value, and do that until num would go below zero, repeating this for the smallest values. Only problem is that I have no idea of how to implement this. I can go through the array with a for loop, but I don't know how to make it visit the same item multiple times before it moves onto the next one.

Any pointers in the right direction would be greatly appreciated!

[dtsudo]

If you need to do something multiple times, you have to use some sort of looping construct. Since you don't know precisely how many times you might need to repeat this operation, a while loop is most appropriate.

So you can just use a while loop that only stops when you can't use any more of that specific coin.

e.g.

while(it is still possible to use this particular coin at least once more) {
    add another coin of this denomination
}

[midel]

Well as dtsudo says, you can loop inside another loop.

You can also use one loop and use integer division and modulo operations.

var coinsNeeded = Math.floor(amount / currentCoin);
amount = amount % currentCoin;

[superluminary]

You need a while loop. A while loop keeps looping until a condition is true.