In every NodeJS program, there is a magic array named argv.

It contains the command line arguments to the program.

If the user types this in the Terminal:

node hello.js Alice Bob

then process.argv contains:



ARGV is a historical name. It means "Argument Vector" and has been around since the early 1970s.

LAB: Command-Line Hello

Write a new program called hi.js that contains:

console.log("Hi, " + process.argv[2] + "!")

and run it a few times from the Terminal, e.g.

node hi Alice
node hi Bob
node hi "good buddy"

LAB: Hi, Everybody!

Change hi.js to say hi to every one of its command line arguments.

For instance:

node hi Alice Bob Charlie
Hi, Alice!
Hi, Bob!
Hi, Charlie!

LAB: Add

Write a program named add.js that adds all of its command line arguments together.


node add 1 2 3 4

Hint: Do you remember how to convert a string to a number?

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