Node JS - Node js REPL More Commands - Node - Node JS tutorial - webnode

This is a node.js tutorial for beginners to teach commands and operators in REPL.
Find Length of an array using underscore ( _ )

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Initialize an array as [1,2,3]. On pressing enter key, the initialized array is displayed as [ 1, 2, 3 ] .
Fetch the length of the array using the node.js command _.length.If we provide (_+1) the output will be displayed as 4.

REPL context and global scope variables

const repl = require('repl');
var msg = 'message';
repl.start('> ').context.m = msg;

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Declaring the variable repl_cmd and specifying it as required field.
Initializing the variable myMsg with the value “WikiTechy”.
Mark the “val” variable as context variable and assign the myMsg value to the val variable.

I placed my file in the path D:\wikiTechy\7.node.js\3.repl-Commands\repl_val.js.
Go to command prompt and type the below command:

node D:\wikiTechy\7.node.js\3.replCommands\repl_val.js -> Press enter key
val -> press enter key

This will display the context of “val” which is placed in the javascript file as shown below:

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Command	Purpose
.break	While inputting a multi-line expression, sometimes you get lost or just don't care about completing it. .break will start over.
.clear	This command will reset the context object to an empty object and clears any multi-line expression.
.exit	It will close the I/O stream, which will cause the REPL environment to exit.
.help	It shows the list of special commands.
.save	This command saves the current REPL session to a file.
.load	It loads a file into the current REPL session.