Читать книгу OCP Oracle Certified Professional Java SE 17 Developer Study Guide - Jeanne Boyarsky - Страница 135

Increment and decrement operators, ++ and --, respectively, can be applied to numeric variables and have a high order of precedence compared to binary operators. In other words, they are often applied first in an expression.

Increment and decrement operators require special care because the order in which they are attached to their associated variable can make a difference in how an expression is processed. Table 2.3 lists each of these operators.

TABLE 2.3 Increment and decrement operators

Operator	Example	Description
Pre-increment	++w	Increases the value by 1 and returns the new value
Pre-decrement	--x	Decreases the value by 1 and returns the new value
Post-increment	y++	Increases the value by 1 and returns the original value
Post-decrement	z--	Decreases the value by 1 and returns the original value

The following code snippet illustrates this distinction:

int parkAttendance = 0; System.out.println(parkAttendance); // 0 System.out.println(++parkAttendance); // 1 System.out.println(parkAttendance); // 1 System.out.println(parkAttendance--); // 1 System.out.println(parkAttendance); // 0

The first pre-increment operator updates the value for parkAttendance and outputs the new value of 1. The next post-decrement operator also updates the value of parkAttendance but outputs the value before the decrement occurs.

For the exam, it is critical that you know the difference between expressions like parkAttendance++ and ++parkAttendance. The increment and decrement operators will be in multiple questions, and confusion about which value is returned could cause you to lose a lot of points on the exam.