Bash Data Types — Bash interactive lesson

Understanding Bash Data Types

This section introduces the different data types available in Bash scripting.

Strings

Strings are sequences of characters used to store text. They can be manipulated using various string operations such as concatenation and substring extraction.

Example: Strings

# String example
greeting="Hello, World!"
name="Alice"
full_greeting="$greeting, $name!"
echo $full_greeting

Numbers

Numbers in Bash can be used for arithmetic operations. Bash supports integer arithmetic natively, such as addition, subtraction, multiplication, and division.

Example: Numbers

# Number example
num1=5
num2=10
sum=$((num1 + num2))
difference=$((num2 - num1))
product=$((num1 * num2))
quotient=$((num2 / num1))
echo "Sum: $sum, Difference: $difference, Product: $product, Quotient: $quotient"

Arrays

Arrays are used to store multiple values in a single variable. Each element in an array is accessed using an index. You can iterate over arrays and modify elements.

Example: Arrays

# Array example
fruits=("apple" "banana" "cherry")
for fruit in "${fruits[@]}"; do
 echo $fruit
done

Associative Arrays

Associative arrays allow you to use named keys to access values. They are similar to dictionaries in other programming languages. You can add or remove keys and values.

Example: Associative Arrays

# Associative array example
declare -A colors
colors[apple]="red"
colors[banana]="yellow"
colors[grape]="purple"
unset colors[banana]
echo ${colors[apple]} # red
echo ${colors[grape]} # purple

Data Type Limitations

Bash does not support floating-point arithmetic natively. For such operations, consider using external tools like bc or awk .

# Number example num1=5 num2=10 sum=$((num1 + num2)) difference=$((num2 - num1)) product=$((num1 * num2)) quotient=$((num2 / num1)) echo "Sum: $sum, Difference: $difference, Product: $product, Quotient: $quotient"