Javascript shift() unshift() mnemonics? [closed]
As I known.
The shift command is come from the binary bit shift [1]. for Example.
0011000 < 011000 // when you shift left|Yay!I think it is quite simple it is just like you push it from behind. So this makes sense for me.
The unshift is the opposite way of shift.
0011001 > 001100 // they called it unshift 1001100 | Yay!So that's it, Hope this helps!
[1] http://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
a.push(e) pushes e onto the end of a.
e = a.pop() pops the last element from a, to e.
a.unshift(e) enqueues e to the start of a.
e = a.shift() gets the first element from a to e.
Use push and pop for stacks.
Use unshift and pop for queues. (Or push and shift)
I remember the difference between shift (destructive) and unshift (constructive) simply by remembering that I use un-shift for en-queueing, and shift is the opposite to unshift.
Just think of your keyboard:
Shift gets a capital version of the first key you press.
.shift() gets the first item off the array.