Have you tested your code beside compiling it? Just a few issues that you may have fixed already.
For example in this code block:
// What are the ints for? The are declared but initialization has not happened
int add, subtract, multiply, divide;
// In this line of code you ask the user to type in desired function (Strings) from the sounds of it but your program expects int. When the user types in add and it expects an int your application will complain and crash. You could rephrase and ask to type the number of function desired sort of a menu or you could also ask for a string but it will be slightly more involved. Not difficult just a little bit of learning.
System.out.println("Please type in the desired function (no caps)-- add, subtract, multiply,"
+ "or divide: ");
int e = scan.nextInt();
// Same as first set of ints created. They are declared but not initialized. Ints can only take whole numbers (1,2,3,4,5...etc)
int Add, Subtract, Multiply, Divide;
Another thing is how are you gonna let your program know what function to do?
if (e == add){
// code
}
else if (e == subtract){
// code
}
//... etc
What is the difference between add and subtract? In the upper portion of your program you assign both of them the same value. How will the application know the difference of an int that is 0 vs an int that is 0? In an if-else statement it will run the first condition that is true. So if they are both set to the same value it will always run add portion.
Keep in mind when Declaring variables it is always
Datatype variableName = some value;
I think you are confusing how to use variables and are mistakenly using the name as a way of differentiating ("add" or "Add") which are actually Strings.