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4.11 COMMON ERRORS IN JAVASCRIPT
                 As you know, JavaScript is an interpreted language, errors in your code can cause it to behave unexpectedly or fail to
                 run correctly in the browser. These mistakes don't always produce detailed error messages, which can make debugging
                 challenging. Some common mistakes that can prevent your JavaScript code from displaying or functioning properly in
                 the browser are as follows:

                 Ð ÐMissing Quotation Marks: Strings in JavaScript must be enclosed in quotation marks ("" or ''), and missing one can
                   result in an error.

                 Ð ÐCase Sensitivity: JavaScript is case-sensitive, so commands like document must be written in lowercase. Writing
                   Document with a capital "D" will result in an error.

                 Ð ÐMissing Parentheses/Brackets: Functions  like document.write() require parentheses to work. If you forget the
                   closing parenthesis, it will throw a syntax error.

                 Ð ÐMissing <script> Tag: JavaScript code in an HTML document must be enclosed within <script> tags. Forgetting either
                   the opening or closing <script> tag will prevent the code from running.

                 Ð ÐMisspelled Variable Names: JavaScript variable names are also case-sensitive, so if you declare a variable but later
                   refer to it with a different case or misspelled name, it will cause an error.

                 Ð ÐMissing Semicolons: While JavaScript can often infer semicolons, omitting them can sometimes cause unexpected
                   behaviour, especially in complex statements or when chaining multiple statements on the same line.

                 Ð ÐUnclosed Comments: Forgetting to close a comment can cause large sections of your code to be ignored by the
                   browser.

                 Ð ÐUsing Undefined Variables: Referencing a variable before it is defined or misspelling a variable name can cause
                   undefined errors or other unexpected results.

                   4.12 THE WRITE() AND WRITELN() METHODS
                 Both methods are used to display output on the web page. The write() method writes straight to an open (HTML)
                 document stream (A stream an object that allows to read/write data). The writeln() method also writes directly
                 to an open HTML document stream, with the addition of writing a newline character after each statement. For
                 example:
                 The following output will be in a single line.

                     document.writeln("I love reading Harry Potter books");
                     document.writeln("I also love reading murder mysteries");
                 The following output will be in two lines.
                     document.writeln("I love reading Harry Potter books");

                     document.writeln("I also love reading murder mysteries");
                 Let us create a JavaScript program:

                    <HTML>
                    <HEAD>

                     <TITLE> Using write() and writeln() Methods </TITLE>
                    </HEAD>
                    <BODY text="blue">
                     <H2> The write() and writeln() Methods </H2>
                    <PRE>

                    <SCRIPT TYPE="text/javascript">
                    document.write("Hello!");
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