ARGV

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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:

[ 
    '/usr/local/bin/node',
    '/Users/alex/code/hello.js',
    'Alice',
    'Bob'
]

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

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"

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!

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

e.g.

node add 1 2 3 4
10

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