#! /bin/bash
echo "select an option ..."
echo " type 1 to have banana "
echo " type 2 to have apple "
echo " type 3 to have pineapple "
echo " type 4 to have coffee "

read choice 

case $choice in 
    1)
        echo " You choose banana "
        ;;
    # "hello") echo "you typed hello";; 
    # *".txt") echo "this is a txt file";; 
    # inside the ), is the condition to check against case statement 
    2)
        echo " You choose apple "
        ;;
    3)
        echo " You choose pineapple "
        ;;
    4)
        echo " You choose coffee "
        ;;
    ## for choice not in number 1 to 4, use * for anything else, then return a statement 
    *) 
        echo " none of the above"
        ;;
esac 

echo " *--------------------------* "

echo " type a character "
read char 

case $char in 
    [0-9])
        echo "using [ ] means any number between 0 and 9, only use single number in [], eg [12-15] won't work, [2-5] works"
        ;;
    1[0-9])
        echo "putting 1 outside [], means any number bween 10 to 19"
        ;;
    [0-9] | [a-z])
        echo "| means or, so number between 0 to 9 OR a to z, not recommend to use many OR conditions"
        ;;
    [a-z])
        echo "any letter, lower case between a to z"
        ;;
    [A-Z])
        echo "any letter, upper case between a to z"
        ;;
    *) 
        echo " none of the above"
        ;;
esac