How to Concatenate Strings in Ruby Using Concat Method?

Introduction

String Concatenation in Ruby can be accomplished using several approaches, including the addition operator (+), the concat ruby method, and the << operator. Each method has its advantages and specific use cases, allowing developers to choose the most suitable approach based on their needs.

Syntax

+ operator:

concat method:

<< operator:

Example 1: Addition Operator (+)

This method is used for concatenating a small number of strings together such as combining a first name and a last name, or building short strings or string literals like creating a greeting message.

The addition operator does not modify the operand strings but produces a new string that represents the concatenation of the original strings. This ensures that the original strings are unchanged, and a newly concatenated string is created.

Let's consider a simple example where we want to concatenate two strings using the addition operator (+):

Output

Explanation

• In this example, we declared two string variables, first_name and last_name, with the values "Rohit" and "Sharma" respectively.
• The addition operator (+) is used to concatenate the first_name, a space character (" "), and the last_name variables.
• The result is stored in the full_name variable.
• Finally, we print the value of first_name and full_name using the puts method, which displays "Rohit" and "Rohit Sharma" in the output. This shows that the operand strings are not modified.

Example 2: Concat Method

The Concat Ruby method is particularly useful when modifying an existing string by appending another string, such as adding a suffix to a filename. It is also beneficial when we need to sequentially append multiple strings.

Now, let's explore an example using the concat method:

Output

Explanation

• In this example, we have the variables first_name and last_name with the values "Rohit" and "Sharma," respectively.
• The concat ruby method is used to concatenate the space character (" ") and the last_name variable to the first_name string.
• The concat ruby method is called with multiple arguments to append the space character and the last_name string to the first_name string in a sequential manner.
• The result is stored in the full_name variable.
• Finally, we print the value of first_name and full_name using the puts method, both of which display "Rohit Sharma" in the output. This shows that the operand strings also get modified in this method.

Example 3: << Operator

Another approach to string concatenation in Ruby is using the << operator. This method is used for modifying an existing string by appending another string, like adding multiple items to a shopping cart. The << operator is especially useful for concatenating strings within a loop or iteration.

Let's see an example:

Output

Explanation

• In this example, we have the variables first_name and last_name with the values "Rohit" and "Sharma," respectively.
• The << operator is used to concatenate the space character (" ") and the last_name variable to the first_name string.
• The << operator modifies the first_name string in place by appending the space character and the last_name string.
• The result is stored in the full_name variable.
• Finally, we print the value of first_name and full_name using the puts method, both of which display "Rohit Sharma" in the output.

The << method is an alias for concat and is used to append one string to another. It is important to note that, starting with Ruby 2.4, there is a difference between the two. The concat ruby method can accept multiple arguments for concatenation, whereas the << method only accepts one argument at a time. This distinction is useful when deciding which method to use based on our concatenation requirements.