How to: Q. What is REPL?
REPL (READ, EVAL, PRINT, LOOP) is a computer environment similar to Shell (Unix/Linux) and command prompt. Node comes with the REPL environment when it is installed. System interacts with the user through outputs of commands/expressions used. It is useful in writing and debugging the codes. The work of REPL can be understood from its full form:

* **Read**: It reads the inputs from users and parses it into JavaScript data structure. It is then stored to memory.
* **Eval**: The parsed JavaScript data structure is evaluated for the results.
* **Print**: The result is printed after the evaluation.
* **Loop**: Loops the input command. To come out of NODE REPL, press ctrl+c twice

Simple Expression

```js
$ node
> 10 + 20
30
> 10 + ( 20 * 30 ) - 40
570
>
```
↥ back to top