Tip of the : Undeclared Variables

tip1.js

//Tip of the day
//Variable declaration 

//Every declaration out of any scope becomes 
//part of the global object like	

var i = 0; 
var j = 0; 
var bar = function () {};
// A common JavaScript bug is with the undecleared variables in any scope they become part of the global object as well

function kiss() { 
	// anti-pattern ↓ 
	// How many kisses you want?
	k = 2; 
	return k;
}

kiss(); // <----- Returns a defined number of kisses
// oh look is part of the global object !!
console.log(k);
console.log(this.k); 
console.log(window.k); // window is reference to the global object in the browser environment.

function kissMe () {
	// anti-pattern ↓ 
	for (k = 0; k < 10000000; k++) {
		kiss();
	}
	return "My job is done here";
} 

kissMe(); // <----- Ask for kisses 10000000 times. 

// Opps we're stuck with infinite kisses :( we are dead now next time declare your variables like this 

function kiss() { 
	var k = 2; // How many kisses mom gave you ?
	return k;
}

function kissMe () {
	for (var k = 0; k < 10000000; k++) {
		kiss();
	}
	return "My job is done here";
} 
kissMe ();