This is a simple test of the use of Global variables in Javascript. Now suppose the following code writing outside of any function, class or whatever.

k = "k";

var t = "t";

alert("gl: " + k);

alert("gl: " + t);

Will alert us of both variables with those nice little javascript alerts

Now suppose we add this function to the code above

function test() {

	alert("t: " + k);

	alert("t: " + t);

	j = "J";

	var l = "l";

	alert("t: " + j);

	alert("t: " + l);

	k = "2k";

	t = "2t";

}

Now we run the test.

test();

which Alerts all the variables.

But now if we try the following:

alert("gl after test: " + k +" - " + "gl after test: " + t);

Alerts us with the following line gl after test: 2k - gl after test: 2t. So Globals can be modified from within functions. But what happens to the variables that were defined within the function?

 alert("gl: " + j);

//alert(”gl: ” + l); //This won’t run, l was scoped within test and can’t be accessed outside of test.

Conclusions: Variables initialized outside a function are global whether you use var or not. Variables initialized inside a function are not global if they are initialized with var, else they are global.