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Stdout writing with Nodejs

I'm starting with some modern Javascript, I decided to use Nodejs, because at the moment it is the most popular structure for JS on the desktop, I don’t understand why my code is not working and the related error message I get.

Consider this snippet

var a = 5;
var func = function(){return arguments.length;};
process.stdout.write(+func(1,2,3,a));

It does not work and generates the following error message

net.js:612
    throw new TypeError('invalid data');
          ^
TypeError: invalid data
    at WriteStream.Socket.write (net.js:612:11)
    at Object.<anonymous> (var_1.js:3:16)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:902:3

I am a C / C ++ programmer, and for me this is absolutely mysterious, moreover, I used it +before the call functo make sure the result integer, so why writecomplain about everyone?

After some nonsense adding + '\n', this code works

var a = 5;
var func = function(){return arguments.length;};
process.stdout.write(+func(1,2,3,a) + '\n');

Can anyone explain what is happening?

+4
3

, 1- .write() String Buffer. Number .

process.stdout.write(func(1,2,3,a).toString());

process.stdout.write(String(func(1,2,3,a)));

(a + b) '\n'.

+8

Buffer . (stdout - .) , stdout .

() , . (i+'') integer toString.

+2
var writeBuffer = Buffer(1);
writeBuffer[0] = 1; //Value to be written
process.stdout.write(writeBuffer);
0

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