OCR GCSE Computer Science: Programming Fundamentals

Programming Fundamentals: GCSE Computer Science Paper 2

This tutorial covers the essential programming concepts assessed in OCR GCSE Computer Science Paper 2.

1. Variables and Constants

Variables are containers that hold data. They are like labelled boxes you can store different values in.

name = "Alice" 
age = 25

Constants are fixed values that cannot change. They are often used for values that remain the same throughout the program.

PI = 3.14159

2. Data Types

Different types of data require different storage methods. Common data types include:

• Integer (int): Whole numbers (e.g., 10, -5)
• Float (float): Numbers with decimal points (e.g., 3.14, -2.5)
• String (str): Text (e.g., "Hello", "World")
• Boolean (bool): True or False values (e.g., True, False)

3. Operators

Operators are symbols that perform operations on data.

Arithmetic Operators:

• + (Addition)
• - (Subtraction)
• * (Multiplication)
• / (Division)
• % (Modulo - remainder after division)

Comparison Operators:

• == (Equal to)
• != (Not equal to)
• > (Greater than)
• < (Less than)
• >= (Greater than or equal to)
• <= (Less than or equal to)

Logical Operators:

• and (True if both operands are True)
• or (True if at least one operand is True)
• not (Reverses the truth value)

4. Input and Output

Input allows users to provide data to the program.

name = input("Enter your name: ")

Output displays information from the program.

print("Hello,", name)

5. Control Structures

Control Structures determine the flow of execution in a program.

5.1. Sequence

Statements are executed in the order they appear.

print("Step 1")
print("Step 2")
print("Step 3")

5.2. Selection (if-else)

Executes different code blocks based on a condition.

if age >= 18:
  print("You are an adult")
else:
  print("You are a minor")

5.3. Iteration (Loops)

Repeats a block of code multiple times.

5.3.1. For Loop: Repeats a fixed number of times.

for i in range(5):
  print("Loop iteration:", i)

5.3.2. While Loop: Repeats as long as a condition is true.

count = 0
while count < 5:
  print("Loop iteration:", count)
  count += 1

6. Programming Examples

Example 1: Calculating the area of a circle

PI = 3.14159
radius = float(input("Enter the radius: "))
area = PI * radius * radius
print("The area of the circle is:", area)

Example 2: Checking if a number is even or odd

number = int(input("Enter a number: "))
if number % 2 == 0:
  print(number, "is even")
else:
  print(number, "is odd")

7. Revision and Practice

Practice writing code using the concepts covered in this tutorial. Work through exercises and past papers to solidify your understanding. Remember to break down complex problems into smaller, manageable steps. Good luck with your GCSE Computer Science exams!