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