Switch statement in Java - Step-by-Step Execution

Concept Flow - Switch statement

Start

↓

Evaluate expression

↓

Match case?

No→default case?

↓

Execute case

↓

Break?

No→Continue to next case

Yes↓

Exit switch

The switch statement evaluates an expression, matches it to a case, executes that case's code, and exits or continues based on break statements.

Execution Sample

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;
  default: System.out.println("Other day");
}

This code prints the day name based on the value of 'day' using a switch statement.

Execution Table

Step	Expression Value	Case Checked	Match?	Action	Output
1	3	case 1	No	Skip
2	3	case 2	No	Skip
3	3	case 3	Yes	Execute and break	Wednesday
4	-	-	-	Exit switch

💡 Execution stops after matching case 3 and encountering break.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
day	3	3	3	3	3

Key Moments - 3 Insights

Why does the switch stop after printing "Wednesday"?

Because of the break statement at case 3 (see execution_table step 3), which exits the switch to prevent running other cases.

What happens if there is no break after a case?

Execution continues to the next case (fall-through). This is not shown here because each case has a break.

When is the default case executed?

Only if no case matches the expression value. Here, day=3 matches case 3, so default is skipped.

Visual Quiz - 3 Questions

Look at the execution table, what is the output at step 3?

A Tuesday

B Wednesday

C Monday

D Other day

💡 Hint

Check the 'Output' column at step 3 in the execution_table.

At which step does the switch statement exit?

A Step 2

B Step 3

C Step 4

D Step 1

💡 Hint

Look at the 'Action' column showing 'Exit switch' in the execution_table.

If the break at case 3 was removed, what would happen?

A Execution continues to default case

B Switch exits immediately

C Only case 3 executes

D An error occurs

💡 Hint

Recall that without break, switch falls through to next cases (see key_moments about break).

Concept Snapshot

switch(expression) {
  case value1: // code; break;
  case value2: // code; break;
  ...
  default: // code;
}
- Evaluates expression once
- Matches cases in order
- Executes matched case code
- break exits switch to avoid fall-through
- default runs if no case matches

Full Transcript

A switch statement evaluates an expression and compares it to each case value in order. When a match is found, it runs the code inside that case. If a break statement is present, it stops and exits the switch. Without break, it continues running the next cases (called fall-through). If no case matches, the default case runs if it exists. In the example, day=3 matches case 3, prints "Wednesday", then break stops further execution.