06-functions

Functions

Parameters

Default values

Arguments

Return

Arrow functions

Syntax

const greetings = (name) => {
  return `Hello, ${name}!`
}

Short syntax

When writing one-line functions (as above) arrow functions allow for very short-form notation when written as a single line. This function exactly replaces the function written above:

const greetings = name => `Hello, ${name}!`

How was this made shorter?

• Omitting the () around the parameters can be done when taking a single parameter.
• The {} around the function body can be removed and the value of the single line (after the =>) is assumed to be returned, therefor no return keyword is necessary.

Scope and this

What makes arrow functions different than standard functions, other than being shorter, is that the variable this is always scoped to the window, rather than to a caller (for example, with an Event handler).

More to come.

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