Java Control Statements Explained: if, else, switch and Loops (Beginner Guide)

Java Control Statements Explained: if, else, switch and Loops

Author: Gursehbaj Singh | Blog: DevMode

Control statements in Java decide the flow of program execution. They help your program make decisions and repeat tasks. In this post, we will learn if, else, switch, and all types of loops in a simple way.

1. if Statement

The if statement runs code only when a condition is true.

int age = 18;

if (age >= 18) {
    System.out.println("You are eligible to vote.");
}

2. if-else Statement

int marks = 40;

if (marks >= 50) {
    System.out.println("Pass");
} else {
    System.out.println("Fail");
}

3. else-if Ladder

int score = 85;

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

4. switch Statement

The switch statement is used when we have many choices.

int day = 2;

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

5. for Loop

Used when you know how many times to repeat.

for(int i = 1; i <= 5; i++) {
    System.out.println(i);
}

6. while Loop

Runs while condition is true.

int i = 1;

while(i <= 5) {
    System.out.println(i);
    i++;
}

7. do-while Loop

Runs at least once, even if condition is false.

int i = 1;

do {
    System.out.println(i);
    i++;
} while(i <= 5);

8. break and continue

for(int i = 1; i <= 10; i++) {
    if(i == 5) {
        break;
    }
    System.out.println(i);
}

for(int i = 1; i <= 5; i++) {
    if(i == 3) {
        continue;
    }
    System.out.println(i);
}

Common Mistakes

• Forgetting break in switch
• Infinite loops
• Wrong condition logic

Conclusion

Control statements are very important in Java. They help your program make decisions and repeat tasks. Once you master if-else, switch, and loops, you can write powerful and logical programs easily.