os=("Ubuntu", "Windows", "MacOS")
# Print all the elements of the array
echo "${os[@]}"
# Print 1st element of the array
echo "${os[1]}"
# Print all the index of the array
echo "${!os[@]}"
# Print length of the array
echo "${#os[@]}"
# Add element to array
os[3]="BSD"
# Remove element from array
unset os[1]