Java Illuminated, 5th Edition

5.1 Forming Conditions

Often in a program, we need to compare variables or objects. For instance, to determine whether someone can shop online, we want to know if the person’s age is at least 18. Or, if we are adding students to the honor roll, we want to add only those students with averages of 90 or better. Similarly, if we are sending warnings to students, we want to send those warnings only to students whose averages are below 60.

Java provides equality, relational, and logical operators to evaluate and test whether an expression is true or false. It also provides selection statements to transfer control to a different part of the program depending on the result of that test.

5.1.1 Equality Operators

A common operation is to compare ...