concept short - circuit operator in category java

This is an excerpt from Manning's book OCA Java SE 8 Programmer I Certification Guide. Login to get full access to this book.

Purpose: To determine whether the operands of an expression that uses the short-circuit operators && and || will evaluate.

Figure A.2. In an expression that uses the short-circuit operators && and ||, the operands that are evaluated are circled and the ones that aren’t evaluated are enclosed in rectangles.

The purpose of the next Twist in the Tale is to encourage you to play with code that uses short-circuit operators. To determine whether a boolean expression passed as an operand to the short-circuit operators evaluates, you can apply a unary increment operator (in postfix notation) to the variable used in the expression. Compare the new variable value with the old value to verify whether the expression was evaluated (answers in the appendix).