Loops and Logic - Beginning Java - page 91

With nested if s, the question of which if statement a particular else clause belongs to often arises. If
you remove the braces from the preceding code, you have:
if(number%2 == 0) // Test if it is even
if(number < 50 ) // Output a message if number is < 50
System.out.println("You have got an even number < 50, " + number);

else
System.out.println("You have got an odd number, " + number); // It is odd

This has substantially changed the logic from the previous version, in spite of the fact that the indentation
implies otherwise. The else clause now belongs to the nested if that tests whether number is less than 50,
so the second println() call is executed only for even numbers that are greater than or equal to 50. This is
clearly not what was intended because it makes nonsense of the output in this case, but it does illustrate the
rule for connecting else s to if s, which is:
An else always belongs to the nearest preceding if in the same block that is not already spoken for by
another else .
You need to take care that the indenting of statements with nested if s is correct. It is easy to convince
yourself that the logic is as indicated by the indentation, even when this is completely wrong.
Let's try the if-else combination in another program.

TRY IT OUT: Deciphering Characters the Hard Way
Create the class LetterCheck , and code its main() method as follows:

public class LetterCheck {
public static void main(String[] args) {
char symbol = 'A';
symbol = (char)(128.0*Math.random()); // Generate a random

character

if(symbol >= 'A') { // Is it A or

greater?
if(symbol <= 'Z') { // yes, and is it Z

or less?

// Then it is a capital letter
System.out.println("You have the capital letter " + symbol);

} else { // It is not Z or

less

if(symbol >= 'a') { // So is it a or

greater?

if(symbol <= 'z') { // Yes, so is it z

or less?

// Then it is a small letter
System.out.println("You have the small letter " + symbol);