Consider the following code
var scope = "global scope";
function checkscope() {
console.log(scope);
var scope = "local scope";
console.log(scope);
}
checkscope();
This prints the following in the console
undefined
local scope
Why is the first console.log printing undefined instead of "global scope"?
It's because of hoisting. Your var keyword is hoisting a new local scope variable to the top of the function, which is undefined.
Your code is the same as:
function checkscope() {
var scope;
console.log(scope);
scope = "local scope";
console.log(scope);
}
To access the global scope from within the function, you would have to reference the global object, which is window for browsers. This will work if the global scope is actually global, and not just in a parent scope of checkscope().
function checkscope() {
console.log(window.scope); // access the global
var scope = "local scope";
console.log(scope);
}
global scope?
var scope; // initially undefinedwindow.scope would work. But don't do that unless you really have to.
scope variable from the global scope then no it's not accessible. If you want to access the global scope variable from in the function then window.scope will work.