I’ve been stuck with this problem. I want a certain variable to accept numbers only. If a user input a letter, number with letter or letter with number it will be ask again to enter a number. Here’s my code so far. It works when the user inputs a letter or a letter before a number but when you put the number first before the letter it still proceed to ask the next question. Please help me out. I’m still a beginner.

Here’s my code so far:

I’ve tried using while loop but it doesn’t seem to work. I used double instead of int since it’s a coding on how a calculator works