Conditional Statements in Java.

Introduction

Jab aap real-life mein decisions lete ho — jaise agar barish ho rahi ho to chhata leke jao — waise hi Java programs mein bhi decision-making hoti hai. Iske liye use kiya jata hai Conditional Statements.

Java mein mainly 4 types ke conditional statements hote hain:

1. if statement
2. if-else statement
3. if-else-if ladder
4. switch-case statement

Chaliye sabko ek-ek karke samajhte hain with easy examples.

1. if Statement

Agar condition true hai, toh code block chalega. Nahi toh skip ho jayega.

Syntax:

if (condition) {
    // true hone par ye code chalega
}

Example:

int age = 20;
if (age >= 18) {
    System.out.println("You can vote!");
}

2. if-else Statement

Agar condition true hai toh if wala part chalega, warna else wala.

Syntax:

if (condition) {
    // true block
} else {
    // false block
}

Example:

int age = 16;
if (age >= 18) {
    System.out.println("You can vote!");
} else {
    System.out.println("You are underage.");
}

3. if-else-if Ladder

Jab multiple conditions check karni ho, tab iska use hota hai.

Syntax:

if (condition1) {
    // code 1
} else if (condition2) {
    // code 2
} else {
    // default code
}

Example:

int marks = 75;

if (marks >= 90) {
    System.out.println("Grade: A");
} else if (marks >= 75) {
    System.out.println("Grade: B");
} else if (marks >= 60) {
    System.out.println("Grade: C");
} else {
    System.out.println("Grade: D");
}

4. switch-case Statement

Jab aapko ek variable ke multiple exact values ke basis pe decision lena ho, tab switch-case kaafi useful hota hai.

Syntax:

switch (expression) {
    case value1:
        // code
        break;
    case value2:
        // code
        break;
    default:
        // code
}

Example:

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");
}

When to Use What?

• Simple true/false: if
• 2 choices: if-else
• Multiple ranges: if-else-if
• Exact match from fixed values: switch-case

Final Thoughts

Java mein conditional statements ki madad se aap smart aur dynamic programs bana sakte ho. Inka sahi use karke aap real-world logic easily implement kar sakte ho.

Code likhte time:

• Har condition ko clearly define karo.
• break likhna switch case mein mat bhoolna.
• Readability maintain karo for better debugging.