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If Statement in Java

  • An if statement in Java is a control flow statement that allows your program to execute a certain block of code only if a specified condition is true.

  • Think of it as giving your program a choice: "If this condition is true, then do this."

  • if statements is crucial because they allow your programs to make decisions based on certain conditions.

Syntax of an if Statement​

Here is the basic syntax of an if statement in Java:

if (condition) {
    // code to be executed if the condition is true
}

  • condition: A boolean expression (an expression that evaluates to either true or false).

  • code block: The set of statements that will be executed if the condition is true. This block is enclosed in curly braces {}.

How It Works​

When an if statement is encountered, the condition inside the parentheses is evaluated:

  • If the condition is true, the code block inside the curly braces {} is executed.

  • If the condition is false, the code block is skipped, and the program continues with the next statement after the if block.

Example of an if Statement​

Let's look at a simple example to understand how an if statement works. Consider the following code:

public class Main {
    public static void main(String[] args) {
        int number = 10;

        if (number > 0) {
            System.out.println("The number is positive.");
        }
    }
}

Explanation:​

  1. Declaration of the variable: We declare an integer variable number and assign it a value of 10.

  2. The if statement: We check if number is greater than 0 using the condition number > 0.

  3. Code block: If the condition is true, the code inside the curly braces {} will execute, printing "The number is positive."

Since number is indeed greater than 0, the output of this program will be:

The number is positive.

Summary​

  • if statement: Executes a block of code if a condition is true.

  • Condition: A boolean expression that determines whether the code block will be executed.

  • Code block: The statements that run if the condition is true, enclosed in curly braces {}.

The if statement is a powerful tool for making decisions in your Java programs.