JavaScript Switch case

JavaScript Switch case is used to execute a block of statement out of multiple blocks of statements based on a condition. JavaScript switch is a condition-based statement that has multiple conditions but executes only one block at a time.

In switch statement, the switch expression is evaluated only once and then the output is compared with every case mentioned inside the switch block and if the output of expression matches one of the cases then the statement written inside the block of that case is executed. If no case matches then the default case is executed.

JavaScript switch case is used in applications where you have to implement a menu like system in which based on user input certain action is taken.

JavaScript switch: Syntax

The expression which evaluates the condition is written inside the switch(expression), followed by a curly bracket which creates a switch block in which the different cases are defined.

switch(expression)
{
case 1:
    //code
    break;
case 2:
    //code
    break;
default:
}

Based on the value of the expression's output, one of the many cases gets executed, and then the break statement is called which breaks the execution, and the switch case gets exited.

NOTE: If we do not add the break statement after the code statements in the switch case block, then the interpreter would execute each and every case after the matched case.

JavaScript Switch case: Example

In this example, we are using the switch case and each case executes based on the provided value.

In the above example, we have used the break statement to terminate the switch case.

JavaScript Switch Case Example without break

Use of the break statement is optional, if we don't use it then the switch case does not terminate and executes all the rest of the cases till the end, after the matched case. See the below example:

JavaScript Switch Case Default

The default statement is executed if the switch expression output does not match with any of the given cases. In the below example we have shown this scenario:

With this, we have covered the JavaScript switch statement. Although if else statements are popular and used in most of the cases, in some scenarios having using switch statement makes the code more readable and scalable. So choose wisely, what to use when.