電卓を作成しようとしています。
echo "What is your number?"
read n1
echo "what is your second number?"
read n2
echo "what do you want to do?"
echo "1. add"
echo "2. subtract"
echo "3. divide"
echo "4. multiply"
read ans
if
ans=$(( $n1+$n2 )); then
echo $ans
elif
ans=$(( $n1-$n2 )); then
echo $ans
elif
ans=$(( $n1/$n2 )); then
echo $ans
elif
ans=$(( $n1*$n2 )); then
echo $ans
else
ただし、文字を挿入すると0が表示されます。どのように改善できますか？時には間違った答えを与えるかもしれません。
ベストアンサー1
以下を試してくださいwhile loop。
input="yes"
while [[ $input = "yes" ]]
do
PS3="Press 1 for Addition, 2 for subtraction, 3 for multiplication and 4 for division: "
select math in Addition Subtraction Multiplication Division
do
case "$math" in
Addition)
echo "Enter first no:"
read num1
echo "Enter second no:"
read num2
result=`expr $num1 + $num2`
echo Answer: $result
break
;;
Subtraction)
echo "Enter first no:"
read num1
echo "Enter second no:"
read num2
result=`expr $num1 - $num2`
echo Answer: $result
break
;;
Multiplication)
echo "Enter first no:"
read num1
echo "Enter second no:"
read num2
result=`expr $num1 * $num2`
echo Answer: $result
break
;;
Division)
echo "Enter first no:"
read num1
echo "Enter second no:"
read num2
result=$(expr "scale=2; $num1/$num2" | bc)
echo Answer = $result
break
;;
*)
echo Choose 1 to 4 only!!!!
break
;;
esac
done
done