AP CSP Day 4 - Strings and String Operations
AP CSP Day 4 - Strings and String Operations
Course Information
- Course: AP Computer Science Principles
- Unit: Big Idea 1 - Creative Development (CRD)
- Lesson: Day 4 (50 minutes)
- Learning Objective: CRD-1.D - Use strings and string operations appropriately
Learning Objectives
Primary Goals
Students will be able to:
- Define what a string is
- Understand how string operations work
- Create and manipulate strings in programs
- Perform common string operations
AP Exam Alignment
- Big Idea 1: Creative Development (10-13% of AP Exam)
- Essential Knowledge: CRD-1.D.1, CRD-1.D.2, CRD-1.D.3
- Computational Thinking Practice: 1.A - Investigate the situation, context, or task
Lesson Structure (50 minutes)
Opening Hook (10 minutes)
1.1 Welcome & Lesson Preview (5 minutes)
Teacher Activities:
- Recap previous day's content on expressions and operators
- Introduce today's topic on strings and string operations
Student Activities:
- Think about: "What are some examples where we use strings in daily life?"
1.2 String Examples Challenge (5 minutes)
Activity: "Identify the String Operation"
Instructions:
- Groups of 4-6 students
- Identify string operations in given scenarios
- Discuss the importance of strings
Purpose: Activate thinking about strings
Core Content Instruction (20 minutes)
2.1 What are Strings? (10 minutes)
Definition (CRD-1.D.1):
A string is a sequence of characters.
Key Concepts:
- String literals: "Hello", 'World'
- String concatenation: Combining strings
- String indexing: Accessing individual characters
Case Study: Using strings in a simple program
- Program: Greeting program
- Strings: name = "John"; greeting = "Hello, " + name
2.2 Common String Operations (5 minutes)
Examples:
- Concatenation: str1 + str2
- Indexing: str[0]
- Slicing: str[1:4]
Discussion Questions:
- What makes a good string operation?
- Can you think of an example where strings are used in daily life?
- Why are strings important in programming?
2.3 Advanced String Operations (5 minutes)
Why is it important?:
- Methods: len(), upper(), lower()
- Formatting: f-strings, format()
Discussion Questions:
- How can we manipulate strings effectively?
- Why are advanced string operations useful in programming?
Hands-On Activity (15 minutes)
3.1 Group Project: Create a Program with Strings (15 minutes)
Activity: "Design a Program"
Instructions:
- Groups of 3-4 students
- Design a program that uses strings
- Present the program to the class
Materials:
- **Program design worksheet
- **String usage checklist
Learning Goals:
- **Define a string
- **Use strings in a program
- **Perform common string operations
- **Present ideas effectively
Assessment:
- **Group participation
- **Program quality
- **Presentation clarity
Closure & Preview (5 minutes)
4.1 Key Concepts Review (2 minutes)
Today's Learning Highlights:
- ✅ Understanding what a string is
- ✅ Identifying examples of strings
- ✅ Creating and manipulating strings in programs
- ✅ Performing common string operations
AP Exam Connection:
- These concepts will appear in AP exam multiple choice questions
- Understanding strings is crucial for the Create Performance Task
4.2 Next Class Preview (3 minutes)
Day 5 Topic: "Algorithm Design and Testing"
- Learning Objective: CRD-1.E - Develop algorithms to solve problems
- Activity: Practicing algorithm design
- Homework: Think about a recent program you used. What string operations did it employ?