push, pop, unshift, and shift

Four crucial array methods allow one to add and remove elements from the front or back of an array. push adds an element to the end of an array, while pop removes an element from the end of the array. push takes an argument (the element to be added) and returns the modified array. pop takes no argument and returns the element removed. Both methods modify the original array.

The shovel operator (<<) is functionally equivalent to push, but it allows for the simpler syntax typical of operators. Note that << does not concatenate. Shoveling one array into another creates a nested array:

To perform actions similar to push and pop except for the front of the array rather than the end, you can use the methods unshift and shift. Both modify the original array.