Switch statement in Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a switch statement used for in JavaScript?

A switch statement is used to perform different actions based on different conditions. It checks a value against multiple cases and runs the matching block of code.

beginner

How do you write a basic switch statement syntax?

Use switch(expression) { case value1: // code break; case value2: // code break; default: // code } to compare the expression with values and run matching code.

intermediate

What happens if you forget to add break in a switch case?

Without break, the code will continue running the next cases even if they don't match. This is called "fall-through" behavior.

beginner

What is the purpose of the default case in a switch statement?

The default case runs if none of the other cases match the expression. It acts like a fallback or else condition.

intermediate

Can a switch statement compare different data types?

Yes, but the comparison uses strict equality (===), so the type and value must match exactly for a case to run.

What keyword stops the execution of more cases in a switch statement?

A stop

B break

C exit

D return

The break keyword stops the switch from running the next cases.

What happens if no case matches and there is no default case?

A Nothing happens, switch ends

B The switch runs the first case

C An error is thrown

D The program crashes

If no case matches and no default is provided, the switch does nothing and continues.

Which comparison does switch use between expression and case values?

A Strict equality (===)

B Less than (<)

C Greater than (>)

D Loose equality (==)

Switch uses strict equality (===), so type and value must match.

Can multiple cases share the same code block in a switch?

A Only if they have the same value

B No, each case must have unique code

C Yes, by stacking cases without break

D Only inside the default case

You can stack cases without break to share the same code block.

What is the role of the default case?

A To stop the switch statement

B To declare variables

C To repeat the first case

D To run code if no other case matches

The default case runs when no other case matches the expression.

Explain how a switch statement works and why you need the break keyword.

Think about how you choose actions based on different options.

Describe what happens if you omit the default case in a switch statement.

Consider what happens when none of the options fit.