Using JavaScript to Write into a Web Page

In JavaScript, if you want to write anything into the web page, you would use document.write(...). This is the correct method as a part of Document Object Model (DOM) API for modifying the contents of a webpage. In the question provided, document.write(...) is the correct answer.

document.write(...)

This is a method that is used to write a string of text, HTML expressions or JavaScript code directly into a page. The document.write(...) statement can be used in a variety of ways. For example:

document.write("Hello World!");

When this JavaScript code executes, it writes the string "Hello World!" directly onto the HTML document.

document.write(5 + 6);

This example shows how JavaScript expressions can be passed to document.write(...). The output would be "11".

document.write("<h1>Welcome to my website</h1>");

You can even write HTML tags directly into the document, which the browser will then render accordingly. In this case, it would display "Welcome to my website" as a header on the webpage.

Best Practices and Additional Insights

However, be aware that document.write(...) has some limitations and is considered a poor practice in modern web development for the following reasons:

1. The function only works properly with inline scripts. If used with an external script (scripts linked via <script src="..."></script>), it can cause the page to overwrite and return unexpected results.

2. The function document.write(...) is blocking. This means the function halts the rendering of the page until it is fully executed, which can slow down your webpage's load time.

3. If document.write(...) is called after the page has finished loading, it will overwrite the entire page, which is usually undesired behavior.

In conclusion, while document.write(...) is good for learning the basics, you should probably avoid using it in production-level code. For dynamic modification of webpage contents, more modern and efficient methods would be innerHTML, textContent, or the createElement and appendChild functions.