Single-Line to Multi-Line ES6 Fat Arrow Function?

Question

I\'m learning ES6 fat arrow functions. What is the correct way to change this code, so as to be able to put another line, even const a = 100; in the place indic

Answer 1

If you want to convert the following method into having more lines:

{
  filter: appointment => true
}

You have to add curly braces and a return statement:

{
  filter: appointment => {
    // ... add your other lines here
    return true;
  }
}

Answer 2

filter: appointment => true,
...

is (and parentheses aren't needed around true) a shortcut for

filter: appointment => {
  return true;
},
...

which is a shortcut for

filter: function (appointment) {
  return true;
}.bind(this),
...

Any amount of lines can be added before return statement.