1. Function Declaration
2. Function Expression
3. Anonymous Function Expression
4. Arrow function

Function Declaration

When a function is starting with keyword function that kind of function is known as function declration.

ex-

function add(a,b){
return a+b
}
add(1,2)
3

Function Expression

When a function is starting with expression that kind of function is known as function expression.

• Expression is anything that results into value
• The function that stored in a variable known as function expression
• In function expression you can avoid the name of the function because in function expression name has no Use
• function name is optional
• In function expression you will always call the function with the name of the variable not with name of the function.

ex-

const addnumber = function add (num1,num2){
return num1 + num2
}
add(10,12)
22

Anonymous Function Expression

When there is no name to function that kind of function is known as Anonymous function

ex-

const addnumber = function (num1,num2){
return num1 + num2
}
addNumber(10,10)
20

Arrow Function

Arrow function is a shorter way of writting @Anonymous function

• The way you make it short is by removing keyword function from it
• You add special sambol ( => eqaul to ,greater than) known as aerrow
• Remove function and replace with ( => )aerrow
• You can never name a Arrow function
• Arrow function always be anonymous ex-

  const addnumber = (num1,num2) =>{
  return num1+num2
  }
  addNumber(2,3)
  5