The syntax for declaring a variable comes in two varieties, depending on whether you initialise the variable aswell.

	//to declare a variable
	type name;
	//to declare a variable an initialise it to the given value.
	type name = expression;

Now that you have a variable, you can use it in expression inbetween operators, or pass it to other methods, or assign it new values.

If you try and use a variable that has been declared, but not assigned a value, in general you will get an error since it hasn't been initialised.

With variables of a user-defined class type, you do not need to use an initialiser, as they are implicitly created for you when you declare them. (Note: in Java this is not the case)