Good question! It’s essential to allocate the correct amount of memory for the data types we want to store.

When you use malloc(n * sizeof(double)), you're telling the program to allocate memory for n number of double values. Each double typically takes 8 bytes of memory. Therefore, by calculating n * sizeof(double), you're ensuring you get enough space for all the doubles you intend to store. If we only allocated ptr with an address without specifying the correct size, there might not be enough memory for all your doubles, leading to errors or program crashes.

So, we need to explicitly allocate n * sizeof(double) to ensure we have enough memory for all n double values you want to work with. Hope this helps!

Hello Prinnie! The issue is with your SQL statement is that you can't use multiple ORDER BY clauses in the same query.

Instead, you should separate the columns by commas within a single ORDER BY clause. For example, if you want to sort the results first by name, then by country, and finally by purchase_amount, you can do it like this:

SELECT *
FROM Customers
ORDER BY name, country, purchase_amount;

This way, all the sorting is done in one go, and you will get the results in the order you expect. Let me know if you have more questions!

Hello Ramyasri.

An exception is not raised automatically for every error.
A catch block runs only if something is thrown.

Case 1: When you don’t need throw

Some C++ operations already know how to handle failure.
Memory allocation with new is one of them.

If new fails:

• C++ automatically throws an exception

• Control jumps directly to catch

• You don’t need to write throw yourself

So it feels like “magic”, but it’s actually built-in behavior.

Case 2: When you do need throw

In normal program logic (conditions, calculations, validations) and the current task in the lesson is calculation:

• C++ does not assume anything is an error

• Even if something is “wrong” by your logic, C++ keeps running

• No exception exists unless you explicitly create one

So unless you write throw, there is:

• No exception

• Nothing for catch to catch

• No error message

I hope I was able to explain it clearly. If you still have any confusion, please feel free to message me again and I’ll be happy to explain it in more detail.

Thank you for your question. keep up the great work in your learning journey! I look forward to hearing more questions from you.

Hi Rishabh! That's a great question and a common point of confusion for many learners just starting with SQL. Let's dive into it:

Why Use VARCHAR for Phone Numbers?

Even though phone numbers consist of digits, we treat them differently from regular numbers like age or ID. Here's why:

• Fixed Format: Phone numbers often have leading zeros or country codes, and using an int would strip those away (e.g., +04123456789).

• Non-Numeric Characteristics: Since phone numbers aren't used for calculations (like operations or comparisons), they are better stored as strings.

Give it a try and let me know if you run into any issues or have further questions. Happy querying! 🙂

Hi Alice 😊

A command line argument is a value you pass to a program when you run it from the terminal. These values tell the program what data it should work with or what action it should perform.

For example, if you have a program that adds numbers, you can run it like this:

./add 10 20

Here, 10 and 20 are the command line arguments. The program reads these values and uses them to calculate the result.

I hope this explains the concept clearly 😊 Please let me know if you need any further help.

Hello Woi Shingo! The </code> tag includes the <code>name</code> attribute to identify the data that the text area collects when the form is submitted. This is a common aspect of form elements, which are grouped together within a form tag.</p><p>When a form is submitted, the values of the form inputs are sent to the server. The <code>name</code> attribute gives a unique identity to each input, helping the server distinguish between the different pieces of data.</p><p>For example, in your current HTML code:</p><pre><code class="language-html"><form action="/html-form-submit" method="post"> <label>Write a movie plot.</label><br> <textarea name="plot" rows="3" cols="40">

Here, name="plot" tells the server that whatever text the user enters into the text area should be associated with the plot identifier once the form is submitted.

Consider this scenario:

Imagine needing to capture both a movie title and its plot in a form. You might adjust your code to look like this:

    Movie Title:

    

    Write a movie plot:

    

Here, you'd have two inputs each with a different name:

1. name="title": captures the movie title.

2. name="plot": captures the movie plot.

When this form is submitted, the server will know exactly which text is the title and which is the plot.

Hope this helps make sense of the name attribute! Let me know if you have more questions, or if there's anything else you'd like to understand better. 😊

Hello Arun! The != symbol is known as the "not equal to" operator in Python. It checks whether two values are not equal to each other. Here's how it works:

• It returns True when the values are different.

• It returns False when the values are the same.

For example, in the code you're working with:

number = 21

# This will print False because 21 is equal to 21
print(number != 21)

# This will print False because 50 is equal to 50.0
print(50 != 50.0)

# This will print True because 21 is not equal to 21.1
print(number != 21.1)

In the first two cases, both values are equal, so it prints False. In the last case, 21 is not equal to 21.1, so it prints True.

Keep practicing with these comparison operators, and you'll get the hang of them! If you have more questions, feel free to ask!

The next() and nextLine() methods are both part of the Scanner class in Java and are used for reading input from users, but they serve slightly different purposes:

• next(): It reads the next token (word) from the input, stopping at whitespace (spaces, tabs, or newlines).
  
  For example, if the user inputs Maria Smith, calling next() would only return Maria on the first call and Smith on the second call.

• nextLine(): It reads the entire line of input until it hits a newline character (when the user presses Enter).
  
  So in the case of the same input Maria Smith, calling nextLine() would return Maria Smith all at once.

As highlighted in your lesson, it's recommended to use nextLine() when you want to capture full inputs that may consist of multiple words, like names or sentences, without worrying about spaces.

This is particularly useful in scenarios where the input contains spaces, and you want to ensure you capture everything as a single string.

If you have any more questions about these methods or anything else, feel free to ask! Hope this helps!

Hi there! Wildcards in SQL make it easier to search for data when you don’t know the exact value.

Different databases use slightly different wildcard symbols, so here’s a quick and easy explanation for SQL Server, MS Access, and SQLite.

In SQL Server:

• The % symbol matches any number of characters. For example, 'a%' finds values that start with “a”.

• The _ symbol matches exactly one character, so 'a_' finds two-letter values starting with “a”.

• You can also use square brackets like [a-f] to match any single character between “a” and “f”.

• To exclude characters, use [^a-f] or [!a-f], which means anything not in that range.

In MS Access, the wildcards are slightly different:

• The * symbol works like % and matches any number of characters.

• The ? symbol represents exactly one character.

• The # symbol matches a single digit (0–9).

• You can also use brackets like [abc] to match a, b, or c, and ![abc] to match anything except those letters.

In SQLite, wildcards work the same way as in SQL Server:

• % matches any number of characters

• _ matches a single character.

All of these wildcards are used with the LIKE operator to filter results more flexibly depending on your database system.

For more detailed explanations and examples of each wildcard, you can check this link:

https://dbschema.com/blog/tutorials/sql-wildcard-characters/#:~:text=In%20SQL%2C%20a%20wildcard%20character,specified%20pattern%20in%20a%20column.

Hope this helps! Let me know if you’d like more examples or support.

Hi there! Great question, let’s clear it up for you.

A pointer is indeed a type of variable in C programming. But, unlike regular variables that store actual values, a pointer stores the address of a variable in memory.

Think of a pointer like a directional sign pointing to where something is stored, rather than what is stored there. When you create a pointer for an integer with int* pt;, you're essentially saying, "I want pt to hold the address of a memory location that contains an integer." This is why we use the symbol * in pointers—it denotes that the variable is meant to store a memory address.

So, yes, while a pointer is a kind of variable, it differentiates itself by holding addresses rather than values directly. Remember, the variable that pt points to will be manipulated by accessing the address stored in pt.

Hope this helps! Let me know if you have more questions or need further clarification.