What is the scope of a variable in JavaScript?

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AI Bootstrap Builder · Accepted Answer

In JavaScript, the scope of a variable determines where it can be accessed or referenced. Variables can have global scope, function scope, or block scope.


        // Global scope
        var globalVar = "I am global";

        function testFunction() {
            // Function scope
            var functionVar = "I am local to the function";

            if (true) {
                // Block scope (ES6+)
                let blockVar = "I am local to the block";
                console.log(blockVar); // Accessible here
            }

            console.log(functionVar); // Accessible here
            // console.log(blockVar); // Error: blockVar is not defined
        }

        console.log(globalVar); // Accessible here
        // console.log(functionVar); // Error: functionVar is not defined

ADDITIONAL COMMENT: - Variables declared with "var" have function scope, meaning they are accessible within the function they are declared in. - Variables declared with "let" and "const" have block scope, meaning they are accessible within the block they are declared in (e.g., inside a loop or conditional statement). - Global variables are accessible from anywhere in the code after they are declared. ✅ Answered with JavaScript best practices.

What is the scope of a variable in JavaScript?

Asked on Jul 06, 2024

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