In programming, functions are like little machines that perform specific tasks. Sometimes, these tasks need to be flexible, and that’s where parameters come in. Let’s explore how parameters make functions more useful and powerful.
Imagine you have a function called moveForward that moves a turtle 25 pixels forward. This is fine if you always want to move exactly 25 pixels, but what if you want to move different distances? Instead of writing a new function for each distance, you can use a parameter. A parameter is like a special input that tells the function how far to move the turtle. This makes your function more versatile.
Let’s look at an example. Suppose you have a function that draws a square with sides 100 pixels long. If you want to draw a square with sides 50 pixels long, you might think you need a new function. But there’s a better way! By using a parameter, you can create one function that draws squares of any size.
Here’s how it works: you define a parameter called “size” in your function. Whenever you want to use the size of the square, you use the word “size” instead of a specific number. This way, when you call the function, you can specify any size you want, like 63 pixels, and the function will draw a square with sides that long.
When you call a function with a parameter, you provide a value that gets “passed” to the function. Think of the parameter as a container with a label. The value you pass is stored in this container, and inside the function, you use the parameter’s name to access the value. This makes your function adaptable to different situations.
Once you’ve mastered using a single parameter, you might want to add more. For example, you could add parameters to change the color or width of the lines in your square-drawing function. Just separate each parameter with a comma, and when you call the function, provide a value for each one.
Using parameters is a great example of abstraction in programming. Abstraction helps you solve a group of related problems by identifying patterns. By using parameters, you can create a single function that handles many different situations, reducing the need for duplicate code. This makes your programs easier to read, write, and maintain.
In summary, parameters are a powerful tool in programming. They allow you to create flexible and efficient functions that can handle a variety of tasks. By understanding and using parameters, you can write better code and become a more skilled programmer.
Design a simple function that uses a parameter to perform a task of your choice. For example, create a function that calculates the area of a rectangle using length and width as parameters. Share your function with the class and explain how the parameters make it versatile.
Work in pairs to create a game where you write functions with parameters to control a character’s movement on a grid. Use parameters to change the distance and direction of the movement. Challenge your partner to navigate a maze using your functions.
Use a programming tool like Scratch or Python Turtle to draw shapes. Write a function that draws a polygon, using a parameter to specify the number of sides. Experiment with different values and observe how the shape changes.
Write a short story where each character has a unique action that is controlled by a function with parameters. For example, a character might jump a certain height or speak a certain number of words. Share your story with the class and discuss how parameters enhance the narrative.
Participate in a class challenge where you are given a task, such as drawing a specific pattern or solving a math problem, and must write a function with parameters to complete it. Present your solution and explain how parameters helped achieve the task efficiently.
Here’s a sanitized version of the provided YouTube transcript:
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We’ve already seen that some functions are defined with parameters to make them more generally useful. For example, the original version of `moveForward` moved the turtle exactly 25 pixels. This doesn’t give you a lot of options for designing your drawings. A much more useful version of `moveForward` is one that accepts a parameter that allows you to specify exactly how far forward the turtle should move. Up to this point, the functions we’ve written ourselves don’t have parameters. However, the ability to write your own function with parameters is both useful and powerful. So, let’s see how to do it.
Here’s an example: look at this function that draws a square with sides that are 100 pixels long. If we wanted to make a function to draw a square with sides 50 pixels long, we’d have to create a new function that’s almost identical to the first one, with the only difference being how far the turtle moves each time. If we wanted even more options for the size of the square, we would need to declare a new function each time. That’s not very efficient. Luckily, there’s another way.
The solution to this problem is the ability to create a function that accepts a parameter. A parameter is a named value provided as input to a function. We saw that our version of `drawSquare` has a lot of repeated code. The turtle was executing the same basic behavior, just moving by different amounts. We can express this generalized behavior in our code as well.
Here’s a new version of `drawSquare`. In this version, the size of the square is a parameter of the function. Notice that the function heading declares that it needs an input. We’ve given a name to that input, which is “size.” Everywhere in the code where we need to use that value, we enter the word “size” instead of a specific number.
Writing a function with a parameter is very similar to writing a function without one. Just drag the function block that shows a parameter and drop it into the workspace. We add the name of our parameter inside the parentheses in the function call. Just as giving a meaningful and descriptive name to your function is important, so is deciding what to name a parameter. The name of a parameter should give some insight into what the value will be used for. In this case, we’ve chosen the name “size” to indicate that you can set the size of the square when calling the function.
As a programmer, what you call your parameter is your decision to make. We can write the body of a function like this: the parameter “size” acts as a placeholder for that value. Wherever we want to use that value, we refer to it as “size” instead of a specific number.
Let’s look at what happens when the function is called. Now, when a user calls `drawSquare`, they call it with a value like this. We say the value of 63 gets “passed” to the parameter of the function. The parameter acts like a container with a name on it. Whatever value is passed into the function is stored in that container. Inside the body of the function, you’ll want to use the value stored in the parameter. To do so, you must refer to the value by its name. As the program runs, whenever the word “size” is encountered, it’s replaced by the value stored in that parameter.
Adding a parameter to our `drawSquare` allows us to generalize its functionality. In other words, our function is useful in a range of situations, rather than just one specific instance. The result is a function that gives you much more flexibility and control without the need to create duplicated code.
Once you’ve added a single parameter to your function, you might realize that there are multiple aspects of its functionality you’d like to generalize. For our square example, you might want to change the width or color of the line. To do this, you can simply add more parameters and separate them by commas. You can then use any of these parameter names in the body of your function. When calling your function, you’ll need to include multiple values—one for each of the parameters, separated by commas.
Parameters are another example of how abstraction can be used to solve problems. When confronted with a group of related problems, we first work to identify patterns across all of them. In doing so, you might realize that using parameters will let you define a single function with general behavior that can solve any instance of the problem with one piece of code. This is a powerful skill that removes the need for creating duplicate code and leads to programs that are easier to read, write, and maintain.
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This version maintains the original content’s meaning while removing any informal language and ensuring clarity.
Programming – The process of designing and building an executable computer program to accomplish a specific task. – Example sentence: “In our computer class, we learned the basics of programming by creating a simple calculator application.”
Functions – Reusable pieces of code that perform a specific task and can be called upon multiple times within a program. – Example sentence: “Using functions in your code can make it more organized and easier to debug.”
Parameters – Variables that are used to pass information into functions, allowing them to perform tasks with different inputs. – Example sentence: “When defining a function, you can specify parameters to customize its behavior.”
Turtle – A graphics library in Python that allows for unique and creative drawing using code. – Example sentence: “We used the turtle module to draw geometric shapes on the screen in our coding class.”
Size – The dimensions or amount of space taken up by an object, such as a file or a graphical element in a program. – Example sentence: “Adjusting the size of the window can help fit more information on the screen.”
Value – The data stored in a variable, which can be a number, text, or other types of data. – Example sentence: “Changing the value of a variable can alter the outcome of a program’s execution.”
Adaptable – Capable of being modified to suit different conditions or uses, especially in programming. – Example sentence: “Writing adaptable code ensures that your program can handle various inputs and scenarios.”
Color – An attribute that defines the appearance of an object in terms of hue, saturation, and brightness, often used in graphics programming. – Example sentence: “We learned how to change the color of text and shapes in our web design project.”
Width – The measurement of how wide an object is, often used in programming to define the size of elements like lines or borders. – Example sentence: “By increasing the width of the line, we made the drawing more visible on the screen.”
Abstraction – A concept in programming that involves hiding complex details to simplify problem-solving and focus on high-level operations. – Example sentence: “Using abstraction, we can manage complex systems by breaking them down into simpler parts.”
