Global Scope means the defined data type can be accessed from anywhere in a JavaScript program. JavaScript Global Scope concept is related Variables.
let a = "Global Scope";
function greet () {
console.log(a);
}
A variable declared outside of a function is considered a global scope variable. This variables can be accessed from anywhere in a JavaScript program.
JavaScript Global Scope
Simple example variables declared with var
, let
and const
are quite similar when declared outside a block.
<!DOCTYPE html>
<html>
<body>
<script>
var x = "Global";
let y = "Scoop";
const z = "Example";
function print(){
console.log(x,y,z)
}
print();
</script>
</body>
</html>
Output:

The value of a global variable can be changed inside a function.
<script>
let a = "Hello";
function greet() {
a = 100;
}
console.log(a);
greet();
console.log(a);
</script>
Output:
Hello
100
If a variable is used without declaring it, that variable automatically becomes a global variable.
function greet() {
a = "hello"
}
greet();
console.log(a); // hello
Do comment if you have any doubts or suggestions on this Js scope topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version

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