Programmer's Guide to Java Certification 2nd

3.8 Boolean Expressions

Boolean expressions have boolean data type and can only evaluate to the values true or false.

Boolean expressions, when used as conditionals in control statements, allow the program flow to be controlled during execution.

Boolean expressions can be formed using relational operators (see Section 3.9, p. 67), equality operators (see Section 3.10, p. 67), logical operators (see Section 3.11, p. 70), conditional operators (see Section 3.12, p. 72), the assignment operator (see Section 3.4, p. 47), and the instanceof operator (see Section 6.6, p. 264).