C++ numeric types are similar to those in Java, with a few exceptions. We will mostly use only two numeric types: int for integers and double for real numbers.
See additional numeric types if you are interested.
x + y
| x + y is the sum of x and y. |
x − y
| x − y is the difference, x − y. |
− x
| − x is the negation of x. |
x * y
| x * y is the product x times y. |
x / y
|
x / y is the quotient x divided by y.
Important: If x and y are both integers then x/y is also an integer. Anything after the decimal point is ignored. So 7/4 has value 1, not 1.75. |
x % y
| x % y is the remainder when you divide integer x by integer y. For example, when you divide 14 by 3 you get a quotient of 4 and a remainder of 2. So 14 % 3 = 2. You can only use the % operator on integers. |
Operator * has higher precedence than operator +. For example, expression 2 + 5 * 2 has value 12, since the multiplication is done first.
Operators *, / and % have the same precedence, and operators + and - have the same precedence.
All of the numeric operators are performed from left to right, except where precedence rules and parentheses force otherwise. For example, 10 − 2 − 3 has value 5, but 10 − (2 − 3) has value 11.
Notice that 16/2*2 has value 16 since * and / have the same precedence. The division 16/2 is done first, and then the result of that division is multiplied by 2. If you want 16/(2*2), be sure to use parentheses.
Numbers are converted automatically from one type to another where necessary. For example, 2 is converted to 2.0 if it occurs where a value of type double is needed.
Converting an integer to a real number is usually harmless. Converting a real number to an integer throws away everything after the decimal point. So if 2.7 occurs in a place where an integer is required, it is converted to 2. Watch out for that.
You can request conversions explicitly. If T is a numeric type, then write (T) in front of an expression to convert the value of that expression to type T. For example, expression (int)(x + y) is the value of x + y converted to type int.
What is the value of expression 9 − 6 + 3? Answer
What is the value of expression 3/5? Answer
What is the value of expression 25 % 4? Answer
What is the value of expression 0 % 5 Answer
Is [3 + 2] * 8 an allowed C++ expression? Answer