Which of the following statements is true regarding JavaScript functions?a)JavaScript functions can only be declared using the function keywordb)JavaScript functions can be used before they are declared (hoisting)c)JavaScript functions cannot have default parameter valuesd)JavaScript functions cannot return a valueCorrect answer is option 'B'. Can you explain this answer?

Question

Answer

JavaScript functions can be used before they are declared due to hoisting, which moves function declarations to the top of the scope.

Answer

Hoisting in JavaScript
Hoisting is a JavaScript mechanism where variables and function declarations are moved to the top of their respective scopes before the code is executed. This means that regardless of where functions and variables are declared in the code, they are accessible and can be used before they are actually declared.

Explanation of Option B
The correct statement regarding JavaScript functions is option B: 'JavaScript functions can be used before they are declared (hoisting).'

Hoisting of Function Declarations
When a JavaScript file is executed, function declarations are hoisted to the top of their current scope. This means that you can call a function before it is declared in the code. The JavaScript interpreter moves the function declaration to the top, allowing you to use it anywhere in the code, even before its actual declaration.

Example
Consider the following example:

```javascript
console.log(add(2, 3)); // Outputs 5

function add(a, b) {
return a + b;
}
```

In this example, the function `add` is called before its declaration. However, due to hoisting, the function is moved to the top and can be used without any errors. The output of the above code will be `5`, as expected.

Hoisting of Function Expressions
It's important to note that hoisting works differently for function expressions. Function expressions are not hoisted to the top of the scope like function declarations. If you try to use a function expression before its declaration, you will encounter a 'not defined' error.

Conclusion
In conclusion, JavaScript functions can indeed be used before they are declared due to hoisting. This is an important concept to understand in order to write clean and organized JavaScript code. However, it's worth noting that hoisting can sometimes lead to confusion and unexpected behavior, so it's generally recommended to declare functions before using them for better code readability.

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