JavaScript Arrow function

Javascript Arrow function came into ES6 (ECMAScript 6). Arrow functions don’t bind this keyword to the object.
Arrow functions are best for callbacks or methods like map, reduce, or forEach, etc.

in Arrow function do not write function keyword.

Syntax:-

arrow_function_name:()=>{
return 'Hello';
}

Example:- Suppose, you have a greetings object and that has the say_hello method without parameter..

let greetings={
say_hello:()=>{
return 'Hello';
}
}
console.log(greetings.say_hello());

Syntax:-

arrow_function_name:(param1, param2)=>{
return param1+param2;
}

Example:- Suppose, you have a greetings object and that has the say_hello method with parameter friend_name.

let greetings={
say_hello:(friend_name)=>{
return 'Hello '+friend_name;
}
}
console.log(greetings.say_hello('Rom'));

Suppose, you have employee object and you want to call first_name and last_name through this keyword in full_name method then output will show undefined.

let employee = {
  first_name: 'John',
  last_name:'Taylor',
  full_name: () => { 
    console.log(this.first_name+' '+this.last_name)  
  }
}
employee.full_name();

Suppose, you have employee object and you want to call first_name and last_name through this keyword in full_name method then output will show first_name and last_name values.

let employee = {
  first_name: 'John',
  last_name:'Taylor',
  full_name: function () { 
    console.log(this.first_name+' '+this.last_name)  
  }
}
employee.full_name();