Function scope in JavaScript refers to the scope of variables and functions that are defined within a function. Variables and functions declared with the var
keyword have function scope.
Variables declared inside a function are accessible only within that function and any nested functions. They are not accessible outside of the function in which they are defined. This means that variables declared within a function cannot be accessed before their declaration or outside of the function.
Example: Here, the variable x
is declared inside the exampleFunction()
function. It is accessible within that function and also within the innerFunction()
nested inside it. However, x
is not accessible outside of exampleFunction()
.
function exampleFunction() {
var x = 10; // Variable x has function scope
console.log(x); // Output: 10
function innerFunction() {
console.log(x); // Output: 10
}
innerFunction();
} exampleFunction(); // console.log(x); // Error: x is not defined |
10 10