How to Use Blocks in Java

By Doug Lowe from Java For Dummies Quick Reference

A block in Java is a group of one or more statements enclosed in braces. A block begins with an opening brace ({) and ends with a closing brace (}). Between the opening and closing braces, you can code one or more statements. For example:

{
    int i, j;
    i = 100;
    j = 200;
}

A block is itself a type of statement. As a result, any time the Java language requires a statement, you can substitute a block to execute more than one statement.

You can code the braces that mark a block in two popular ways. One way is to place both braces on separate lines and then indent the statements that make up the block:

if ( i > 0)
{
    String s = “The value of i is “ + i;
    System.out.print(s);
}

The other style is to place the opening brace for the block on the same line as the statement that the block is associated with:

if ( i > 0) {
    String s = “The value of i is “ + i;
    System.out.print(s);
}

Even though a block can be treated as a single statement, you should not end a block with a semicolon. The statements within the block may require semicolons, but the block itself does not.