Introduction
Similar to a Bash script where you can pass arguments to a script using the $1
syntax, you can also pass arguments to a Node.js app.
In this quick tutorial, you will learn how to pass arguments to a Node.js app using the process.argv
array.
Prerequisites
Before you get started, you will need to have Node.js installed:
Pass arguments to a Node.js app
Let's start by creating a new file called script.js
and adding the following code to it:
const process = require('process');
console.log(process.argv[2]);
A quick rundown of the process.argv
array:
-
process.argv[0]
is the path to the Node.js executable -
process.argv[1]
is the path to the script file -
process.argv[2]
is the first argument passed to the script -
process.argv[3]
is the second argument passed to the script and so on
Let's run the script with the following command:
node script.js DevDojo
# Output:
DevDojo
Printing all arguments
To print all arguments, you can use a forEach
loop just as you would with a standard array:
const process = require('process');
process.argv.forEach((val, index) => {
console.log(`${index}: ${val}`);
});
Let's run the script with the following command:
node script.js hi there devs
We are now passing 3 arguments to the script and in this case, the output of this script will be:
0: /opt/homebrew/Cellar/node@16/16.16.0/bin/node
1: /Users/bobby/dev/script.js
2: hi
3: there
4: devs
Conclusion
This is pretty much it! I hope that you find this useful!
In case you are new to Node.js I could suggest the following tutorial on how to get started:
How To Write Your First Node.js Script
To learn more about arguments in Bash scripts, you can read the following article:
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