Push vs Append in Ruby: Key Differences and Usage

In Ruby, push and append are identical methods used to add elements to the end of an array. Both modify the original array and can take one or more arguments. They are interchangeable with no difference in behavior.

Quick Comparison

Here is a quick side-by-side comparison of push and append methods in Ruby arrays.

Factor	push	append
Purpose	Add element(s) to the end of an array	Add element(s) to the end of an array
Syntax	array.push(element)	array.append(element)
Arguments	One or more elements	One or more elements
Return Value	Modified array	Modified array
Mutates Original Array	Yes	Yes
Introduced In Ruby Version	All Ruby versions	Ruby 2.5 and later

Key Differences

Both push and append methods serve the same purpose: adding elements to the end of an array. They accept one or more arguments and modify the original array in place, returning the updated array.

The main difference is historical and stylistic. push has been part of Ruby since the beginning and is widely used. append was introduced in Ruby 2.5 as an alias for push to provide a more readable and intuitive method name, especially for beginners or those coming from other languages.

Functionally, there is no difference in how they work or perform. Choosing between them is mostly a matter of personal or team style preference.

Code Comparison

Using push to add elements to an array:

ruby

arr = [1, 2, 3]
arr.push(4)
arr.push(5, 6)
puts arr.inspect

Output

[1, 2, 3, 4, 5, 6]

append Equivalent

Using append to do the same as push:

ruby

arr = [1, 2, 3]
arr.append(4)
arr.append(5, 6)
puts arr.inspect

Output

[1, 2, 3, 4, 5, 6]

When to Use Which

Choose push when working with legacy code or when you want to use the traditional and widely recognized method name. Choose append when you prefer clearer, more descriptive code that explicitly states adding to the end, especially if you are teaching or learning Ruby. Both are interchangeable, so consistency within your codebase is the key.

Key Takeaways

push and append do the same thing: add elements to the end of an array.

Both methods modify the original array and return it.

append was introduced in Ruby 2.5 as a more readable alias for push.

Use either method based on style preference or code consistency.

There is no performance or functional difference between them.