jQuery variable scope issue in function containing ajax() [duplicate]

This question already has an answer here:

As we know if we call a function multiple times, the variables don't conflict with each other as they have different scope, for ex. new_var is different in both invocations of a function any_function

new_var

any_function

function any_function(argument1)
new_var = argument1;
alert(new_var);


any_function("hello i am first");
any_function("hello i am second");


But I have a function which does an ajax call, when I call this function multiple times, the variable new_var, gets modified according to the last call (invocation) and I always get the same value for all the invocations of the function do_ajax()

new_var

do_ajax()

function do_ajax(argument1)
// var new_var = argument1;
new_var = argument1;
$.ajax(
url : window.location.href,
success: function(r)
alert(new_var);

);

do_ajax("first ajax done");
do_ajax("second ajax done");


You can see the results here https://codepen.io/nikhilnagpal123/pen/XPrvxa

And another interesting thing is if I put var before the variable new_var then I get the expected results

var

new_var

https://codepen.io/nikhilnagpal123/pen/oPNvXJ

from this, I can guess that somehow the variable gets modified, but how can another invocation of that function modify that variable, but there shouldn't be the conflict, they should have different scope,

Could someone explain it pls?

Sorry, Above Question is kind of stupid one, Basically, when we declare a variable inside a function without var we give that function a global scope and that variable can be accessed globally

var

for ex.

function any_function(argument1)
new_var = "hello";


any_function("hello");

alert(new_var); //global variable, also can be accessed by window.new_var

But if I use var when declaring the variable, it will have a local scope only

var

function any_function(argument1)
var new_var = "hello";


any_function("hello");

alert(new_var); // can not be accessed globaly `new_var` scope was only limited to function `any_function` where it was decalred

So in the above question, the last ajax call modifies the global variable when I don't use var while declaring them,

var

I had this wrong conception in my mind that when we don't declare a variable outside the function, it would always have a local scope inside the function where we declare it doesn't matter whether we use var or not, that created the whole misunderstanding,

var

Thanks to the users @Alex and @mplungjan for making things clear for me.

Thanks!

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