Associative Arrays for Key-Value Data

Associative Arrays for Key-Value Data

Associative arrays (hashes/maps) map arbitrary string keys to string values (Bash 4.0+):

# MUST be explicitly declared with -A
declare -A ports=(
    ["http"]="80"
    ["https"]="443"
    ["ssh"]="22"
)

# Adding or updating
ports["dns"]="53"

# Querying keys and values
echo "SSH port: ${ports["ssh"]}"

# Iterating over all keys
for service in "${!ports[@]}"; do
    echo "Service $service runs on port ${ports[$service]}"
done