CodeParkThe main difference is this. An arrow function has no this of its own. It uses the this of the surrounding code where it was defined. call, apply and bind cannot change it.
This makes arrows a good choice for callbacks inside methods. It makes them a bad choice for object methods that need this to be the object.
Arrow functions also lack some things that regular functions have:
- no own
argumentsobject, so use rest parameters like(...args)instead - no
superand nonew.target - they cannot be constructors, so calling them with
newthrows aTypeError - no
prototypeproperty - they cannot be generators
The syntax is also shorter. A concise body returns its value without the return keyword: x => x * 2. To return an object literal this way, wrap it in parentheses: () => ({ a: 1 }).
- An arrow function takes
thisfrom where it was written, not from how it is called. - Arrow functions have no
arguments,super,new.targetorprototype. - Arrow functions cannot be used with
new. - They are good for callbacks, but poor for object methods and prototype methods.
- A concise body like
x => x * 2returns its value automatically.