Blocks with a single statement

There’s a minor point to be made about statement blocks that has the potential to be a source of trouble if we’re not careful. If a code block associated with either a conditional statement or a loop has a single statement in it, the curly braces are not required. For instance in the program above, we could have had

if (num < 0.0)

System.out.println(“You entered a negative value.”);

With the curly braces omitted, any statement that follows println would not be part of the if block. The same goes for loops. Consider the following for loop:

for (int i = 0; i < 10; i++)

System.out.println(i);

System.out.println(“Done.”);

The code will print out the values 0 to 9, each on a line, and finally the message “Done.”