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Java Switch Statement

What is a switch Statement?

A switch statement is another decision-making tool, like if-else. It’s useful when you want to check a variable against many values. Instead of writing many if-else if-else, switch can be cleaner and easier to read.

Check this value and run the block of code that matches it.

Basic Syntax

Java

switch (variable) {
    case value1:
        // code to run if variable == value1
        break;
    case value2:
        // code to run if variable == value2
        break;
    ...
    default:
        // code to run if none of the cases match
}

Key points

variable can be int, char, String, or enum.
Each case checks a possible value of the variable.
break stops the program from running all the next cases.
default runs if no case matches (like else in if-else).

Example – Day of the Week

Java

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;
    case 4:
        System.out.println("Thursday");
        break;
    case 5:
        System.out.println("Friday");
        break;
    case 6:
        System.out.println("Saturday");
        break;
    case 7:
        System.out.println("Sunday");
        break;
    default:
        System.out.println("Invalid day");
}

Wednesday

Note

Here, day == 3 → it prints "Wednesday".

How switch Works

Java checks the variable against all the cases from top to bottom.
If it finds a match, it runs that case.
break prevents it from running all the remaining cases (called "fall-through").
If no match is found, the default block runs.

Example – Multiple Cases Together

Sometimes you want the same code for multiple values:

Java

char grade = 'B';

switch (grade) {
    case 'A':
    case 'B':
    case 'C':
        System.out.println("You passed!");
        break;
    case 'D':
    case 'F':
        System.out.println("You failed!");
        break;
    default:
        System.out.println("Invalid grade");
}

You passed!

When to Use switch vs if-else

Use Case	Recommendation
Few conditions, complex expressions	if-else
Many fixed values of a single variable	switch
Checking ranges (e.g., score > 50)	if-else
Checking exact matches (e.g., day == 3)	switch

Common Mistakes to Avoid

Warning

Forgetting break → causes "fall-through". Using non-compatible types (e.g., float or boolean not allowed in switch). Forgetting default (optional, but useful for invalid values).

Quick Tips

Tip

switch = simpler if-else for many discrete values. Always add break unless you want fall-through. default = optional but recommended. Works well with int, char, String, enum, but not float or boolean.

Practice Exercises

Print the name of a month given its number (1–12).
Print whether a character is a vowel or consonant.
Create a simple calculator using switch (input operator +, -, *, /).
Convert a numeric score to grades using switch (e.g., 1 = A, 2 = B).