The switch statement

A switch statement is the same as to many if statements put together. It has the following syntax:

switch (condition) {
  case 'some-value':
    // Do something
    break
  default:
    // Do something
    break
}

• switch will run if the condition evaluates to true.
• case tests whether the condition is strictly equal to a value.
• break ends the switch statement

The most common use-case for switch is to check whether a string is a certain value.

const hobby = 'some-value'

switch (hobby) {
  case 'basketball':
    // Do stuff if hobby === 'basketball'
    break
  case 'soccer':
    // Do stuff if hobby === 'soccer'
    break
  default:
  // Do stuff hobby is neither basketball nor soccer
}

Doing the same thing for many cases

You can do the same thing for many cases if you omit the break keyword. Here’s an example:

switch (hobby) {
  case 'basketball':
  case 'soccer':
    categorizeUnderBallRelatedSports()
    break
  default:
  // Something else
}

Semicolons

If you run a single function within each case, it may be neater to use a semicolon to separate lines of code.

switch (hobby) {
  case 'basketball':
    basketball()
    break
  case 'soccer':
    soccer()
    break
  default:
  // Do stuff hobby is neither basketball nor soccer
}

Switch vs if

I prefer using if statements over switch statements. I only use switch when I want to use early returns, but I can’t.

We’ll see an example of this in the next lesson when refactoring the calculator.