Java Conditional Statements

Java conditional statements are used to control the flow of execution in a program based on specific conditions. These conditions evaluate to either true or false. Conditional statements allow decision-making and execution of specific code blocks depending on whether the condition is met.

Here’s a detailed explanation of Java's primary conditional statements, with syntax and examples:

1. if Statement

The if statement checks a condition. When the condition evaluates as true, the code block inside the if statement is executed

if (condition) {
    // Instructions to run if the condition is true
}

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

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

Explanation:

Here, the condition number > 0 is evaluated. Since 10 > 0 is true, the message "The number is positive." is displayed.

2. if-else Statement

The if-else statement provides an alternative path of execution if the condition evaluates to false.

if (condition) {
    // Instructions or code  to run if the condition is true
} else {
    // Instructions or Code to execute if the condition is false
}

public class IfElseExample {
    public static void main(String[] args) {
        int number = -5;

        if (number > 0) {
            System.out.println("The number is positive.");
        } else {
            System.out.println("The number is not positive.");
        }
    }
}

Explanation:

If number > 0 is false (as in this case), the code in the else block executes, displaying "The number is not positive."

3. if-else-if Ladder

This allows checking multiple conditions in a sequential manner.

if (condition1) {
    // Code if condition1 is true
} else if (condition2) {
    // Code if condition2 is true
} else {
    // CActions to perform if none of the conditions are met.
}

public class IfElseIfExample {
    public static void main(String[] args) {
        int marks = 75;

        if (marks >= 90) {
            System.out.println("Grade: A");
        } else if (marks >= 75) {
            System.out.println("Grade: B");
        } else if (marks >= 50) {
            System.out.println("Grade: C");
        } else {
            System.out.println("Grade: F");
        }
    }
}

Explanation:

The conditions are checked in order, and the first condition that evaluates to true determines which code block runs. Here, marks >= 75 is true, so "Grade: B" is printed.

4. switch Statement

A switch statement checks the value of a variable or expression and runs the corresponding case block.

switch (expression) {
    case value1:
        // Code to execute if expression == value1
        break;
    case value2:
        // Code to execute if expression == value2
        break;
    // Additional cases
    default:
        // Instructions or code  to execute if no case matches.
}

public class SwitchExample {
    public static void main(String[] args) {
        int day = 3;

        switch (day) {
            case 1:
                System.out.println("Monday");
                break;
            case 2:
                System.out.println("Tuesday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            default:
                System.out.println("Invalid day");
        }
    }
}

Explanation:

The switch statement compares the variable day with each case. If it matches 3, it runs the related code and exits the switch

Key Points to Remember:

Always use {} braces for blocks in if, else, and else if statements, even for single-line statements, to improve readability and avoid errors.
switch is ideal for situations with multiple discrete options.
Avoid forgetting the break statement in switch cases to prevent unintended fall-through behavior.

This detailed breakdown should give you a clear understanding of Java conditional statements!

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Java Conditional Statements