Write Java programs for the following:

1. swap two Number with third variable.
2. swap two number without third variable.
3. Area of triangle.
4. Arithmatic operations on two number.
5. Check the case of character.
6. Currency Converter.
7. Even or odd.
8. Largest of two numbers.
9. Add two numbers without + Operator.
10. Check if triangle is valid or not.
11. Java Program to Generate the Fibonacci Series
12. Java Program to Check Leap Year
13. Largest of three numbers.