Challenges in nodejs

challege1.js

var fs   = require("fs");
var file = "file.txt";


function main(contents){
	var sum = 0;
	var digits = [];
	var chars = {};
	for(var i=0;i<contents.length;i++) {
		var n = contents[i];
		// is it a number?
		if (parseInt(n, 10).toString() === n.toString()) {
			sum += parseInt(n, 10);
			digits.push(n);
		}
		// if key not defined, create it
		if (typeof(chars[n]) === 'undefined') {
			chars[n] = 1;
		} else {
			chars[n] += 1; 
		}
	}
	console.log('Sum = ' + sum);
	for (i in chars) {
		if (chars.hasOwnProperty(i)) {
			console.log(i + ' = ' + chars[i]);
		}
	}
}



fs.readFile(file, "utf-8", function (error, data) {
	contents = data.split("\n");
	main(contents);
});

challenge2.js

//
var MAIN = {
	reverse : function(i){
		return i.toString().split('').reverse().join('');
	},
	halfLength: function(i){
		return parseInt(i.toString().length / 2, 10);
	},
	firstHalf: function(i) {
		return i.toString().substring(0, this.halfLength(i));
	},
	secondHalf: function(i){
		return this.reverse(i.toString().substr(((-1)*this.halfLength(i))));
	},
	isPalindrome: function(i){
		if (i.toString().length == 1 ) {
			return true;
		} else {
			return (this.firstHalf(i) === this.secondHalf(i));
		}
	},
	addReverse : function(i) {
		return (parseInt(i, 10)+(parseInt(this.reverse(i), 10)));
	}
};

var MAX_NUM = 10000;
var notfound = [];

for (var n=1; n<=MAX_NUM;n++){
	var LIMIT = 100;
	var iterations = 0;
	var r = n;
	var is_palindrome = false;
	while (iterations < LIMIT && !is_palindrome) {
		reverse = MAIN.reverse(r);
		sum = MAIN.addReverse(r);
		is_palindrome = MAIN.isPalindrome(sum);
		console.log(r + " + "+reverse+" = "+sum);
		r = sum;
		iterations = iterations + 1;
	}
	if (is_palindrome) {
		console.log("PALINDROME FOUND! "+n+" AFTER "+iterations+" ITERATIONS");
	} else {
		notfound.push(n);
		console.log("NO PALINDROME AFTER "+LIMIT+" ITERATIONS! "+n+"");
	}
}
console.log('');
console.log(notfound.join(', '));