firstNumbers=(2 3 5)
secondNumbers=(7 11 13)
allNumbers=("${firstNumbers[@]}" "${secondNumbers[@]}")
#allNumbers is (2 3 5 7 11 13)
#+= with parentheses adds the elements to an existing array
firstNumbers+=("${secondNumbers[@]}")
#firstNumbers is (2 3 5 7 11 13)
#without the parentheses += adds a string to the first element
secondNumbers+=17
#secondNumbers is (717 11 13)
echo "allNumbers is (${allNumbers[*]})"
echo "firstNumbers is (${firstNumbers[*]})"
echo "secondNumbers is (${secondNumbers[*]})"