JavaScript Switch Statement

The switch statement in JavaScript provides a way to perform different actions based on the value of an expression. It is often used as an alternative to a series of if-else statements when there are multiple possible matches for a given value. The basic syntax of a switch statement looks like this:

let expression = value;

switch (expression) {
  case value1:
    // Code to be executed if expression === value1
    break;

  case value2:
    // Code to be executed if expression === value2
    break;

  // Additional cases...

  default:
    // Code to be executed if none of the cases match
}

Example:

let day = 3;
let dayName;

switch (day) {
  case 1:
    dayName = "Monday";
    break;

  case 2:
    dayName = "Tuesday";
    break;

  case 3:
    dayName = "Wednesday";
    break;

  case 4:
    dayName = "Thursday";
    break;

  case 5:
    dayName = "Friday";
    break;

  case 6:
    dayName = "Saturday";
    break;

  case 7:
    dayName = "Sunday";
    break;

  default:
    dayName = "Invalid day";
}

console.log(dayName); // Outputs: "Wednesday"

In this example:

• The switch statement evaluates the value of the day variable.
• Each case represents a possible value of day.
• If a match is found, the corresponding block of code is executed until the break statement is encountered.
• If no match is found, the code inside the default block is executed.

Note that the break statement is crucial to exit the switch block once a matching case is found. If you omit the break, the execution will "fall through" to the next case, and so on.

Switch statements are particularly useful when you have a value that may have multiple possible matches and you want to avoid a series of if-else statements.