Swap Array Elements with JavaScript's ES6

If you are solving a problem and it requires you to swap elements in an array, you might create a function like this:

function swap(array, a, b){
    let temp = array[a];
    array[a] = array[b];
    array[b] = temp;
}

We define a function called swap, and pass in arguments for an array, variable a, and variable b. These represent the values we want to swap.
Next, we declare a temporary variable, temp, and set that equal to the value of a in the array. We need to hold this value in a variable to refer to it later.
Then, we set the value of a in array to the value of b in array.
Finally, we set the value of b in array to the value of our temp variable. Notice that we can't set it to the value of a in array as we have already changed that to equal b's value.

BUT - with ES6, there's a simpler way!

const swap = (array, a, b) => {
    [array[a], array[b]] = [array[b], array[a]];
};

This uses Destructuring Assignment to separate the elements of the array into values that can be reassigned.

To make the code more compact, we declare the function using an arrow function named swap from ES6.
This function takes the same arguments: array, a, b
Instead of requiring the temp variable, we can simply assign the array's value of a and b to the respective opposite value on the right side of the equal sign.