C/C++ Operators

The Basic Operations

Like Python, C-like languages support the core mathematical operations on numerical data types, be they varables, or literals (i.e. symbols like 3 or 4.6754). You can do any of the following:

Operator	Operation
+	Addition
-	Subtraction
*	Multiplication
/	Division

Unlike Python there is no exponentiation operator (i.e. no **), which requires a function call instead.

Logical Operators

Again, as with Python, all the binary logical operators below work in C/C++

Operator	Operation
a == b	equality test
a > b	greater than
a < b	less than
a >= b	greater than or equal to
a <= b	less than or equal to
!a	not
a !=  b	not equal
a && b	and
a || b	or

In C++ these functions return a bool data type which can be equal to true or false (note the capitalization differs from Python). However, thanks to an implicit type conversion rule, all positive integers evaluate to true and the value zero evaluates to false.

Other Useful Operators

Operator	Operation
a++	increment
a--	decrement
a += b	increment by b
a -= b	decrement by b
a % b	remainder
a << 2	bitwise left shift
a >> 2	bitwise right shift

Operators For Completionists

Operator	Operation
&	bitwise and
|	bitwise or
^	bitwise xor
~	bitwise not
?	conditional ternary operator

The Order of Evaluation

There is a well defined default order of evaluation for operators in C/C++ which is worth knowing. The order of evaluation for commonly used operations is:

1. () parentheses

2. ++ and -- increment and decrement

3. * and / multiplication and division

4. + and - addition and subtraction

5. << and >> bitwise left and right shift

6. ==, !=, >, <, >=, <= comparison

7. ! not

8. && and || logical and and or

9. =, +=, etc. (i.e assignment)

Summary

We’ve now revised the basic operations which C++ allows us to apply to values in expressions, most of which have a Python equivalent. In the next section, we will look in more detail at the various control structures C++ supplies to organise, repeat or skip sections of code within a function.