Difference between %w and %W in Ruby

Introduction

In Ruby, arrays are often used to store collections of similar data types, such as strings. To simplify the creation of string arrays, Ruby offers two different percent literals: %w and %W. These literals provide a concise and readable way to define arrays without explicitly using quotes and commas. However, understanding the disparity between %w and %W is crucial to utilize them effectively.

What is the Difference between %w and %W Array Literals in Ruby?

The Lower-Case %w Percent Literal

The %w literal in Ruby is utilized for creating an array of strings, where each string is separated by whitespace. It automatically converts the elements into strings. Special characters or interpolations are not allowed within the elements. The %w literal is commonly used when a simple array of strings needs to be created.

The Upper-Case %W Percent Literal

The %W literal in Ruby serves a similar purpose to %w but offers added flexibility. It allows for string interpolation and the use of escape sequences within the elements of the array. This means that variables can be interpolated within the strings, and special characters such as newline (\n) and tab (\t) can be included. The %W literal is typically used when there is a need for string interpolation or special characters within the array elements.

Ruby developers can choose the appropriate array literal based on their specific requirements by understanding the distinctions between %w and %W. The %w literal is suitable for simple arrays of strings without special characters or interpolation. In contrast, the %W literal provides more flexibility, allowing for string interpolation and the inclusion of special characters within the array elements.

Examples

Let's explore some examples to illustrate the differences between %w and %W:

Using %w

Explanation

In this example, the %w literal is used to create an array of strings: "apple", "ball", and "cat". The whitespace separates each string, and the resulting array contains three elements.

Using %W

Explanation

In the given example, we demonstrate the utilization of the %W array literal in Ruby. This literal offers the advantage of string interpolation, allowing us to include the value of the variable name within the string and incorporate it into the final array. Additionally, we make use of the %W literal to enable the usage of escape sequences like \n, which represents newline characters. These escape sequences are properly incorporated within the resulting array.

Comparison between %w and %W

Explanation

We have a variable called name with the value "Rohit" in the above example. String interpolation does not occur when using the %w array literal. As a result, the array that results is ["Name", "=", "#name"]. Within the array, the variable name is handled as a string literal and is not interpolated.

When using the %W array literal with string interpolation, however, the variable name is interpolated within the array. This yields an array with the items ["Name", "=", "Rohit"]. During the interpolation procedure, the variable name is replaced with its equivalent value, "Rohit".

When it comes to string interpolation within array literals, this example clearly shows the difference between %w and %W. While %w interprets the interpolated variable as a literal string, %W conducts the actual interpolation and replaces the variable in the final array with its given value.