Java if statement

In Java, an if statement is the simplest decision-making statement. It is used to execute a block of code only if a specific condition is true. If the condition is false, the code inside the if block is skipped.

• The condition must evaluate to a Boolean value (true or false).
• If curly braces {} are omitted, only the immediately next statement is considered part of the if block.

Syntax:

if (condition) {
// Statements executed if the condition is true
}

Example: with Curly Braces

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

        // using if statement
        if (i < 15){
            System.out.println("10 is less than 15");
        }

        System.out.println("Outside if-block");

        // both statements will be printed
    }
}

10 is less than 15
Outside if-block

Explanation:

• The condition i < 15 evaluates to true, so the message inside the if block is printed.
• The second System.out.println() executes regardless of the condition.

Example: without Curly Braces

class GFG {
    public static void main(String args[]){
        
        int i = 5;

        // if statement without braces
        if (i > 0)
            System.out.println("i is positive");

        System.out.println(
            "This statement runs regardless of if condition");
    }
}

i is positive
This statement runs regardless of if condition

Explanation:

• Only the first statement after if is executed when the condition is true.
• The second System.out.println() is not part of the if block, so it executes in all cases.

Working of if statement

• Control reaches the if statement.
• The condition is evaluated.
• If the condition is true, the body inside the if block executes.
• If the condition is false, the program skips the if block.
• Flow continues with the statements after the if block.

Flowchart if statement: