Javascript:Guess output if given code

 

Guess output of following code.

Code:

setTimeout((a,b)=>{

  console.log(a+b)

},1000,1,2,3)

Output:

3

Explanation:

Here 1000 is timeout deplay microseconds while parameters 1,2,3 are

parameter for callback function inside setimeout,inner callback function prints

a+b i.e 1+2 i.e. 3