# Descending for loop in solution for Smallest Common Multiple challenge

I don’t understand the for loop in the basic code solution for this challenge.

I don’t get what’s going on in `for (var i = arr[0]; i >= arr[1]; i--)` at all (though I understand the push method).

This is the full solution:

``````function smallestCommons(arr) {
// Sort array from greater to lowest
arr.sort(function(a, b) {
return b - a;
});

// Create new array and add all values from greater to smaller from the
// original array.
var newArr = [];
for (var i = arr[0]; i >= arr[1]; i--) {
newArr.push(i);
}

// Variables needed declared outside the loops.
var quot = 0;
var loop = 1;
var n;

// Run code while n is not the same as the array length.
do {
quot = newArr[0] * loop * newArr[1];
for (n = 2; n < newArr.length; n++) {
if (quot % newArr[n] !== 0) {
break;
}
}

loop++;
} while (n !== newArr.length);

return quot;
}

// test here
smallestCommons([1,5]);
``````

You have a sorted array of 2 items. You start with the first item (arr[0]), and decrement until you hit the second item (arr[1]), pushing every number between arr[0] and arr[1] into the new array.

So, using the example, the loop becomes:

``````for (i = 5; i >= 1; i--) {
newArr.push(i); // (push 5, push 4, push 3, push 2, push 1)
}
``````
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