Subexpressions

The expression 3/4 calls for integer division because both the operands are integers. The expression 3.0/4.0 calls for floating point division because both the operands are floating point. Most of the operators we are interested in take two operands. In each of the following examples the operator has two operands:

34 + 12

19/3

90 - sum

val * x

However, unary operators take just one operand:

+93

-72

+sum

-Math.PI

A binary operator will always have exactly two operands. However, sometimes one or both operands of a binary operator is a subexpression.

A subexpression is a part of an expression that is by itself a correct expression.

Sometimes a subexpression is a constant, like "8". Any expression can be a subexpression of a larger expression. In the following, both operands of the red operator are subexpressions.

2*3 + 8

(x - y) / 2.3

(sum - 2) * (sum + 3)