# int-or-string.sh
a=2334
let "a += 1"
echo "a = $a "
echo
b=${a/23/BB} # Substitute "BB" for "23".
# This transforms $b into a string.
echo "b = $b" # b = BB35
echo "b = $b" # b = BB35
let "b += 1" # BB35 + 1
echo "b = $b" # b = 1
echo # Bash sets the "integer value" of a string to 0.
c=BB34 # c = BB34
echo "c = $c"d=${c/BB/12} # Substitute "12" for "BB"
echo "d = $d" # 1234
let "d+=1"
echo "d = $d" # 1235