Arithmetic is performed using the regular +, -, *, / and % operators for addition, subtraction, multiplication, division and modulus respectively.
As in many programming languages, there are convenient variations on the assignment operator available for arithmetic manipulation as needed, namely +=, -=, *=, /= and %=, corresponding to the appropriate arithmetic operators. Note that unlike some other languages, there are no increment or decrement operators.
If the user does not explicitly initialize a variable, the variable is set to zero. You can have explicitly uninitialized variables by typing a: int = ---. Uninitialized variables have undefined behavior until a value is written to.
Just like the C programming language, *, /, and % operators have higher precedence by default are evaluated first before evaluating + and -. Use parenthesis to change the evaluation order.