the switch statement in javascript

 Selecting from Many Options with Switch Statements:

If you have many options to choose from, use a switch statement. A switch statement tests a value and can have many case statements which define various possible values. Statements are executed from the first matched case value until a break is encountered.

Here is an example of a switch statement:

switch(lowercaseLetter) {
  case "a":
    console.log("A");
    break;
  case "b":
    console.log("B");
    break;
}

case values are tested with strict equality (===). The break tells JavaScript to stop executing statements. If the break is omitted, the next statement will be executed.

Adding a Default Option in Switch Statements:

In a switch statement you may not be able to specify all possible values as case statements. Instead, you can add the default statement which will be executed if no matching case statements are found. Think of it like the final else statement in an if/else chain.

A default statement should be the last case.

switch (num) {
  case value1:
    statement1;
    break;
  case value2:
    statement2;
    break;
...
  default:
    defaultStatement;
    break;
}

Multiple Identical Options in Switch Statements:

If the break statement is omitted from a switch statement's case, the following case statement(s) are executed until a break is encountered. If you have multiple inputs with the same output, you can represent them in a switch statement like this:

let result = "";
switch(val) {
  case 1:
  case 2:
  case 3:
    result = "1, 2, or 3";
    break;
  case 4:
    result = "4 alone";
}

Cases for 1, 2, and 3 will all produce the same result.