Java If Statement

The Java If Statement is one of the most useful decision making statement in real world programming. Java If statement allows the compiler to test the condition first and, depending upon the result it will execute the statements. If the test condition is true then only statements with in the if statement is executed.

Java If Statement Syntax

If statement in Java Programming language has simple structure:

if (test condition)  {
 
    Statement 1;
    Statement 2;
    Statement 3;
    ………….
    ………….
    Statement n;
}

From the above code snippet, If the test condition inside the If statement is true, then the statements (Statement 1, Statement 2, Statement 3, ……., Statement n) will be executed. Otherwise all these statements inside the Java if statement will be skipped. Let us see the flow chart for better understanding.

Flow Chart of a Java If Statement

The following picture will show you the flow chart behind this Java If Statement

If the test condition is true then STATEMENT 1 is executed followed by STATEMENT N. If the condition is False then STATEMENT N is executed. Because, it is out of the if condition block, and it has nothing to do with the condition result. Let us see one example for better understanding.

Java If Statement example

This program for if statement allows the user to enter any positive integer and it will check whether a number is Positive or Not using the if statement

/* Java If Statement example */
package ConditionalStatements;

import java.util.Scanner;

public class IfStatement {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int Number;
		sc = new Scanner(System.in);		
		System.out.println(" Please Enter any integer Value: ");
		Number = sc.nextInt();
		
		if (Number > 1) {
			System.out.println("\n You have entered POSITIVE Number");
		}
	}

}

From the below screenshot you can observe that, we entered 25 as Number and this program will check whether 25 is greater than 1 or not. As we all know that it is True, it is printing (System.ot.println statement) inside the curly brackets ({}}.

NOTE: If statement does not required the curly brackets to hold single statement but for multiple or group of statements it is mandatory. It is always good practice to use curly brackets following the Java If statements.

Let us change the value to check what happens if the condition fails? (number < 1).

It print nothing because we don’t have nothing to print after the if statement block. Hope you are confused with the result, let us see one more example.

Java If Statement example 2

This If statement in program allows you to enter any positive integer and it will check whether a number is Positive or Not using the if statement

package ConditionalStatements;

import java.util.Scanner;

public class IfStatement {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int Number;
		sc = new Scanner(System.in);		
		System.out.println(" Please Enter any integer Value: ");
		Number = sc.nextInt();
		
		if (Number > 1) {
			System.out.println("You have entered POSITIVE Number");
		}
		System.out.println("This Message is coming from Outside the IF STATEMENT");
	}
}

OUTPUT

You can observe from the above output, it printed both the System.ot.println statements because 23 is greater than 1. Let’s try the negative values to deliberately fail the condition

Here, Condition inside the If statement failed (number < 1). It print nothing from the If statement block so it printed only one System.ot.println statement which is outside the statement block.