Controlling the Flow of Your Programs

Imagine paying a bill from your e-wallet. You will only be able to make the payment if the credit balance in your e-wallet is greater than or equal to the bill amount. The following flowchart shows a simple logic that can be implemented:

Figure 2.1: A representative flow chart for an if-else statement

Here, the credit amount dictates the course of action of the program. To facilitate such scenarios, Java uses the if statement.

With the if statement, your application will execute a block of code if (and only if) a particular condition is true. In the following code, if the happy variable is true, then the block of code immediately following the if statement will execute. If the happy variable is not true, then the block of code immediately following the if statement will not execute.

boolean happy = true;// initialize a Boolean variable as true
if (happy) //Checks if happy is true
    System.out...