Array push and pop in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the array_push() function do in PHP?

It adds one or more elements to the end of an array, increasing its size by the number of elements added.

beginner

What does the array_pop() function do in PHP?

It removes the last element from an array and returns that element, reducing the array size by one.

beginner

How do array_push() and array_pop() relate to a real-life stack of plates?

Adding a plate on top is like array_push(), and taking the top plate off is like array_pop(). Both work with the last item added.

intermediate

What happens if you use array_pop() on an empty array?

It returns NULL because there is no element to remove.

intermediate

Can array_push() add multiple elements at once? How?

Yes, by passing multiple values as additional arguments after the array, like array_push($arr, 'a', 'b', 'c').

What does array_pop() return when called on a non-empty array?

A The last element of the array

B The first element of the array

C The entire array

D NULL

array_pop() removes and returns the last element of the array.

Which function adds elements to the end of an array in PHP?

A array_push()

B array_pop()

C array_shift()

D array_unshift()

array_push() adds elements to the end of an array.

What will array_pop() return if the array is empty?

A An error

B NULL

C Zero

D The first element

If the array is empty, array_pop() returns NULL.

How can you add multiple elements to an array at once using array_push()?

A By calling <code>array_push()</code> multiple times

B By using a loop inside <code>array_push()</code>

C By passing multiple elements as arguments in one call

D You cannot add multiple elements at once

You can pass multiple elements as additional arguments to array_push() to add them all at once.

Which of these is a correct way to add 'apple' and 'banana' to the array $fruits?

A array_pop('apple', 'banana', $fruits);

B array_pop($fruits, 'apple', 'banana');

C array_push('apple', 'banana', $fruits);

D array_push($fruits, 'apple', 'banana');

array_push($fruits, 'apple', 'banana'); correctly adds both elements to the array.

Explain how array_push() and array_pop() work in PHP and give a real-life example.

Think about adding and removing plates from a stack.

What happens if you call array_pop() on an empty array? Why is this behavior useful?

Consider what happens when you try to take something from an empty box.