Bash: Associative arrays

In Bash, an associative array is an unordered list of keys and values where both the key and value are strings. See below for the common things you’ll do with an associate array:

#!/usr/bin/env bash

set -euo pipefail

# Declare the array
declare -A person=(
  [name]="Sajad"
  [age]=32
  [location]="Liverpool"
)

# Assign elements to array
person[hobby]="Coding"

# Get length of array
echo "---------------------------------------------"
echo "The length of the array is ${#person[@]}"
echo -e "---------------------------------------------\n"

# Access array elements by key
echo "---------------------------------------------"
echo "Accessing elements by key:"
echo "---------------------------------------------"
echo "Name: ${person[name]}"
echo "Age: ${person[age]}"
echo "Location: ${person[location]}"
echo "Hobby": "${person[hobby]}"

# Loop over keys
echo -e "\n---------------------------------------------"
echo "Looping over keys:"
echo "---------------------------------------------"
for key in "${!person[@]}"; do
  echo "$key"
done

# Loop over values
echo -e "\n---------------------------------------------"
echo "Looping over values:"
echo "---------------------------------------------"
for value in "${person[@]}"; do
  echo "$value"
done

# Loop over keys and values
echo -e "\n---------------------------------------------"
echo "Looping over keys and values:"
echo "---------------------------------------------"
for key in "${!person[@]}"; do
  echo "key: $key, value: ${person[$key]}"
done

The other type of Bash array is an indexed array.