Concatenating string variables in Bash

To concatenate string variables in Bash, you can use different methods to combine their values into a single string.

Using the + operator

You can concatenate string variables using the + operator.

# Declare the variables
first_name="John"
last_name="Doe"

# Concatenate the variables
full_name="$first_name $last_name"

# Print the result
echo "Full Name: $full_name"

Using the ${} syntax

You can also use the ${} syntax to concatenate string variables.

# Declare the variables
fruit="apple"
color="red"

# Concatenate the variables
description="${color} ${fruit}"

# Print the result
echo "Description: $description"

Using string interpolation

String interpolation allows you to combine variables directly within a string.

# Declare the variables
animal="cat"
sound="meow"

# Concatenate the variables within a string
echo "The $animal makes a $sound sound."

Using += operator

The += operator appends the value of one variable to another.

# Declare the variables
greeting="Hello"
name="Alice"

# Concatenate the variables
greeting+=" $name"

# Print the result
echo "$greeting"

Using printf command

The printf command can be used to format and concatenate strings.

# Declare the variables
item="apple"
quantity=5

# Concatenate the variables using printf
output=$(printf "I have %d %ss." $quantity $item)

# Print the result
echo "$output"

Using echo command with multiple arguments

You can also use multiple arguments with the echo command to concatenate strings.

# Declare the variables
language="Bash"
version="5"

# Concatenate the variables using echo
echo "Using" $language "version" $version