Switch and Sort

In a recent react exercise from the Flatiron school, I was required to sort some adorable pigs by either name or weight. Sorting was an entirely new concept for me, in this post, I will discuss how I used to switch method to sort some pigs.

The objective said to sort pigs based on name and weight depending on user selection. There are a few things we need to understand about sorting in Javascript beforehand. The parameters of the sort will always be two comparators. These two comparators must be pure, meaning that the comparators cannot mutate the objects being compared. The must be stable, meaning the comparator returns the same result with the same pair of input.

Additionally, as the values assigned to the comparators will be 1, 0, or -1, the comparators must be reflexive, anti-symmetric , and transitive. So if (A > B) and (B > C), then (A > C). Now on to the sort itself.

const byNameOrWeight = (hogA, hogB) => {
switch( sort ) {
    case 'name':
        if (hogA.name < hogB.name ){
            return -1
        } else {
            return 1
        }
    case 'weight':
        return hogA.weight - hogB.weight
        default:
        return 0
}
}

As seen above, the comparators are hogA and B from the array of pigs. In the first comparison inside the switch, an if statement checks whether hogB is greater (alphabetically) than hog A and if so, assigns a value of -1. This moves the hog to an earlier position in the array. Otherwise the value is 1, returning to a lower position. Using the .name key in the object allows us to utilize the hogs names as the comparators. As comparisons between the hogs are made, names will be sorted alphabetically.

In the second case, we simply return a subtraction of hogB weight from hog A. If hogA weight is negative from being less than B, it will be moved to a lower position in the array. This powerful yet simple tool allows us to sort arrays of objects across a vast number of criteria. Hopefully in my coding career, pigs will just be the beginning.