What is this JavaScript construct called

Question

I've found a JavaScript arrow function that looks something like this:

([a,b,c]) => {
  a = 1;
  b = 2;
  c = 'x';
}

How is this function invoked? Also, what is this construct called?

Answer 1

This is an arrow function, which gets an array as a parameter and destruct the first 3 values into the corresponding parameters - a,b,c . But it must be assigned to a variable or be self invoked.

() => {} - Arrow function

[a,b,c] - Array destructuring

Example

 const func = ([a,b,c]) => { console.log(a); console.log(b); console.log(c); }; func([1,2,3,4]); 

Answer 2

([a, b, c]) => {}

The first part is a destructuring assignment in the parameters, which takes an array as parameter and returns the variables with the values of the position.

The later assignment makes no sense with the given code.