What is REPL

REPL stands for Read Eval Print Loop. It is basically represent a computer environment like Linux/Unix terminal, window console, etc.
It comes with Nodejs package so you do not need to install separately.

firstly open the terminal
run the node command

$ node

now You will see the REPL Command prompt > where you can type any Node.js command

$ node 
>

// Add the two string

> "John"+" "+"Roser"
John Roser

// Add the numeric value

>1+2+4
7

Note:- to terminate the command we use ctrl+c