Why do we create a calculator in Java?

It’s a common beginner project to learn input/output, decision-making, and arithmetic operations. It gives hands-on experience with user interaction and logic building.

What if the user enters a wrong input like a letter instead of a number?

If a non-integer or non-double input is given, the program may throw an error. We can handle it using try-catch blocks or by checking input types beforehand using Scanner.hasNextInt() or hasNextDouble().

Can I perform floating-point calculations in a Java calculator?

Yes, just use double instead of int for storing input numbers. This way, your calculator can handle values like 5.5 or 12.75 without any issue.

How do I handle division by zero in my Java calculator?

Division by zero causes a runtime error. Before dividing, check if the second number is zero. If it is, show a message like "Cannot divide by zero" to avoid a crash.

Can I build a calculator that works with strings?

Yes, but you’ll need to parse numbers from the string and check symbols. This is more advanced but helps if you're creating a calculator that reads full expressions like "5+3".