Salesforce JavaScript Developer Practice Exam

Hoisting is a fundamental concept in JavaScript that allows variables and function declarations to be moved to the top of their containing scope during the compilation phase. This means that you can reference variables before they are actually declared in the code.

When a variable is hoisted, it is initialized with the value of `undefined` until its actual declaration is reached in the code. Consequently, if you try to access a variable before its declaration, JavaScript will recognize it as an existing variable, albeit with an `undefined` value.

This is critical for understanding the behavior of JavaScript, especially when you are working with function expressions and variable declarations. While this feature can add some flexibility to your coding style, it can also lead to confusion if a developer does not recognize how and when variables are hoisted.

The other choices do not accurately represent how hoisting operates in JavaScript. Variables are not immutable after declaration; they can be reassigned unless specifically declared as `const`. Function scopes do not prevent hoisting; in fact, function declarations are also hoisted. Lastly, hoisting applies to both variables and functions, not just constants. Therefore, the role of hoisting allows for the use of variables before their actual declaration, making this understanding essential for