Java Pocket Guide, 4th Edition

Chapter 6. Statements and Blocks

A statement is a single command that performs some activity when executed by the Java interpreter:

GigSim simulator = new GigSim("Let's play guitar!");

Java statements include the following varieties: expression, empty, block, conditional, iteration, transfer of control, exception handling, variable, labeled, assert, and synchronized.

Reserved Java words used in statements are if, else, switch, case, while, do, for, break, continue, return, synchronized, throw, try, catch, finally, and assert.

Expression Statements

An expression statement is a statement that changes the program state. It is a Java expression that ends in a semicolon. Expression statements include assignments, prefix and postfix increments, prefix and postfix decrements, object creation, and method calls. The following are examples of expression statements:

isWithinOperatingHours = true;
++fret; patron++; --glassOfWater; pick--;
Guitarist guitarist = new Guitarist();
guitarist.placeCapo(guitar, capo, fret);

Empty Statement

The empty statement provides no additional functionality and is written as a single semicolon (;) or as an empty block {}.

Blocks

A group of statements is called a block or statement block. A block of statements is enclosed in braces. Variables and classes declared in the block are called local variables and local classes, respectively. The scope of local variables and classes is the block in which they are declared.

In blocks, one statement is interpreted ...