Explain the tasks of terms used in Node REPL

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Following are the terms used in REPL with their defined tasks:

Read: It reads user’s input; parse the input into JavaScript data-structure and stores in memory.

Eval: It takes and evaluates the data structure.

Print: It is used to print the result.

Loop: It loops the above command until user press ctrl-c twice to terminate.

In a Node.js interview, if asked to explain the tasks of terms used in Node REPL (Read-Eval-Print Loop), you would typically cover the following:

  1. Read: The REPL reads the user’s input, whether it’s a single line of code or a multi-line code snippet.
  2. Eval: Once the input is read, the REPL evaluates the input. It processes the input as JavaScript code and executes it.
  3. Print: After evaluating the input, the REPL prints the result. This can be the return value of a statement, the output of a function, or an error message if the input was invalid.
  4. Loop: Finally, the REPL enters a loop where it waits for the next input from the user. This loop continues until the user exits the REPL session.

Additionally, you might want to mention some common commands used within the Node.js REPL:

  • .help: Displays a list of available commands and their descriptions.
  • .break: If you’re in the middle of a multi-line expression, this command allows you to exit without executing the code.
  • .clear: Clears any multi-line expression that you may be in the middle of writing.
  • .exit or .ctrl + D: Exits the Node.js REPL.

These tasks and commands are fundamental to understanding and utilizing the Node.js REPL effectively during development and debugging processes.