---------------------------------------------
-- Version with [[ .. ]] instead of [ .. ] --
---------------------------------------------
-- Either use                              --
-- [ "$1" .. ]                             --
-- or                                      --
-- [[ $1 .. ]]                             --
---------------------------------------------
#!/bin/bash

if [[ $1 = apple ]]
then
    echo "Good, I like Apples"
elif [[ $1 = pear ]]
then
    echo "Good, I like Pears"
elif [[ $1 = banana ]]
then
    echo "Good, I like Bananas"
else
    echo "Oh no, I hate Oranges!"
fi

---------------------------------------------
-- Version with case instead of if         --
---------------------------------------------
#!/bin/bash

case $1 in
apple)
    echo "Good, I like Apples"
;;
pear)
    echo "Good, I like Pears"
;;
banana)
    echo "Good, I like Bananas"
;;
*)
    echo "Oh no, I hate Oranges!"
;;
esac