Switch Statement
Part of the Fundamentals section of Coddy's JavaScript journey. Lesson 27 of 77.
The switch statement is another way to control the flow of your program based on different conditions. It's similar to using if-else if-else, but it can be more concise and readable in certain situations.
Here's how the switch statement works:
switch (expression) {
case value1:
// Code to execute if expression matches value1
break;
case value2:
// Code to execute if expression matches value2
break;
// ... more cases ...
default:
// Code to execute if no case matches
}- The
expressionis evaluated once. - The value of the expression is compared with the values of each
case. - If there is a match, the associated block of code is executed.
- The
breakstatement is used to exit theswitchstatement. Without it, execution would continue to the next case.
- The
defaultcase is optional. It's executed if no other case matches.
Here's an example:
let day = 3;
let dayName;
switch (day) {
case 1:
dayName = "Sunday";
break;
case 2:
dayName = "Monday";
break;
case 3:
dayName = "Tuesday";
break;
// ... cases for other days ...
default:
dayName = "Invalid day";
}
console.log(dayName); // Output: TuesdayIn this example, the switch statement checks the value of day. Since day is 3, the case for 3 is executed, setting dayName to "Tuesday".
Challenge
BeginnerYou will receive a command from the user.
Use a switch statement to set the value of the variable message based on the command.
Set message to:
"System starting"→ if the command is"start""System stopping"→ if the command is"stop""System paused"→ if the command is"pause""System resuming"→ if the command is"resume"
If the command doesn't match any known option, set:
"Unknown command"
At the end, the program will print the value of message.
Your job is to correctly set the value of <strong>message</strong> using a switch statement.
Try it yourself
// Get the command from the user
let command = inp;
// Create a variable to store the message
let message;
switch (command) {
// Write your code here
}
// Print the message
console.log(message);This lesson includes a short quiz. Start the lesson to answer it and track your progress.
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Logical Operators Part 1Logical Operators Part 2Recap - Simple LogicLogical Operators Part 3Type Coercion7Bill Split Calculator
Welcome MessageCalculating The Tip And Total2Variables
NumbersStringBooleanNaming ConventionsEmpty VariablesRecap - Initialize VariablesConstants3Operators Part 1
Arithmetic OperatorsModulo OperatorArithmetic ShortcutsComparison OperatorsStrict vs Loose EqualityRecap - Simple Math6Basic IO
OutputOutput with VariablesType Conversion - Part 1Type Conversion - Part 2Recap - Till 120Recap - True or FalsePractice on your own: Online JavaScript compiler