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Tom Hebbert
3,472 PointsPlease could you explain how it's possible to change the value of a variable with global scope from inside a function?
I don't understand how it's possible to change the value of a variable with global scope from inside a function?
If the variable has already been defined earlier in the code using the let keyword, why does using it without the keyword in a function redefine it?
2 Answers
Peter Vann
36,427 PointsHi Tom!
Think of a global variable as one that is implicitly declared as an attribute of the window object.
So let num1 = 5 is in effect the same as window.num1 = 5
The window object can be accessed anywhere in your code.
Consider this:
let num1 = 5; // Declared globally
const morf = function() {
num1 = 10; // is the same as window.num1 = 10 (global)
window.num2 = 13; // How to declare a global variable inside a function (must use window)
let num3 = 15; // without window num3 won't be global
}
morf();
console.log(num1);
console.log(num2);
console.log(num3)
will log:
10
13
Uncaught ReferenceError: num3 is not defined
I hope that helps.
Stay safe and happy coding!
Tom Hebbert
3,472 PointsThat really helps, thanks Peter.