Steven Miller

Engineering Manager at Segment


Remembering `.shift()` and `.unshift()`

If you’re like me, you forget the difference between .shift() and .unshift() all the time. Here’s a little trick to remembering them. Picture a keyboard. Now think of that keyboard as an array, with the left side of the keyboard corresponding to the front of the array, and the right side of the keyboard corresponding to the back of the array. Imagine yourself pressing down the left shift key. Think of this as “removing” it from the keyboard (array). Similarly, the shift function removes an element from the front of the array. Now picture yourself removing your finger from the left shift key, and it comes back up. You just “added” (or unshifted) an element to the array.