node.js Error - throw new TypeError('first argument must be a string or Buffer');

Question

I\'m trying to implement a basic addition program in node.js that accepts 2 numbers through the URL (GET Request) adds them together, and gives the result.

Answer 1

You're passing numbers to response.write, when they should be strings. Like this:

response.write(total + '');

The variable total contains the number 21 because you passed the query parameters through parseInt() before summing. It will cause an error when sent through response.write unless you convert to a string first, by appending the empty string to it. number1+number2 is OK because they're strings, but their "sum" is "120".

I'd suggest also looking into the node.js package "express". It handles a lot of the basics for a HTTP server so you can write like:

var express=require('express');

var app=express.createServer();

app.get('/add',function(req,res) {
    var num1 = parseInt(req.query.var);
    var num2 = parseInt(req.query.var2);

    var total = num1 + num2;

    res.send(total + '');
});

app.listen(8888);