Functions

Question 1

What is an arrow function?

Answer 1

It is something like this,

let func = (arg1, arg2, …, argN) => expression;

Question 2

what is the arrow function of this

let sum = function(a, b) {
  return a + b;
};

Answer 2

It arrow (or shorter version is this)

let sum = (a, b) => a + b;

Question 3

Rewrite this with arrow function.

function ask(question, yes, no) {
  if (confirm(question)) yes();
  else no();
}

ask(
  "Do you agree?",
  function() { alert("You agreed."); },
  function() { alert("You canceled the execution."); }
);

Answer 3

function ask(question, yes, no) {
  if (confirm(question)) yes();
  else no();
}

ask(
  "Do you agree?",
  () => alert("You agreed."),
  () => alert("You canceled the execution.")
);

Question 4

What is a function expression?

Answer 4

It is a function that allow us to create a function in the middle of an expression.
for example:

let sayHi = function() {
  alert( "Hello" );
};

Question 5

What is a function?

Answer 5

• is a simple set of instruction
• reusable
• perform one action
• basic building blocs of a program

Question 6

Functions have 2 specific things

Answer 6

-function declaration:

function name(parameters){
body
}

-function call:

name(arguments)

Question 7

what is the point of having function with parameters?

Answer 7

It is because different arguments can be passed into the function with a function call and can be changed every time

Question 8

Does an arrow function need a return?

Answer 8

No arrow functions have implicit returns ( they return the value without having to type return)