9. Outline of a Two-way Decision

Answer:
Enter an integer:
17
The number 17 is zero or positive.
Positive numbers are greater than zero.
Good-bye for now
The false block was executed because the answer to the question (num < 0) was false. 
The false block consists of three statements.

Outline of a Two-way Decision

Here is an outline of a two-way decision structure:

// statements that are executed before the decision

if ( condition )
    // true branch

else
    // false branch

// statements that are executed after the branches join together again

Here are some details:

• The condition evaluates to true or false, often by comparing variables and values.
• The else divides the true branch from the false branch.
• The statements after the false branch are always executed.
• A block consists of several statements inside a pair of braces, { and }.
• The true branch can be a block.
• The false branch can be a block.
• There can be as many statements in a block as you need.
• When a block is chosen for execution, the statements in it are executed one by one.

The condition can compare what is held in a variable to other values. You can use the comparisons <, >, and so on. (More about these later.) The first statement after the false branch will be executed no matter which branch is chosen. The if-else is like a fork in the road, but the road always comes together again.

Question 9:
Is the following section of a program correct?
if ( num < 0 )
    System.out.println("The number " + num + " is negative.");   
else
    System.out.println("The number " + num + " is zero or positive.");  
    System.out.print  ("Positive numbers are greater ");  
    System.out.println("than zero. ");    

System.out.println("Good-bye for now");