As i know, Javascript allocates the memory to the variables before executing any piece of code and creates a scope chain depending upon where they placed in the code which can be seen at Sources tab of dev tools while debugging the code.

Ex.

var a1 = 10;
a2 = 10;

But what if we declare a variable without the 'var' keyword. I can't see where the variable 'a2' is stored before executing the code like a1 can be find in the global scope.