Day 14: Libraries and APIs

Learning Objectives

• AAP-3.D: Select appropriate libraries or existing code segments to use in creating new programs.
• AAP-3.E: For generating random values: Write expressions to generate possible values.
• AAP-3.F: For simulations: Explain how computers can be used to represent real-world phenomena or outcomes.

Essential Questions

• How do libraries and APIs help programmers build on existing code?
• How do we effectively use code written by others in our own programs?

Materials Needed

• Presentation slides on libraries and APIs
• Programming environment with available libraries
• Library exploration worksheet
• API documentation examples
• Exit ticket templates

Vocabulary

• Library
• API (Application Programming Interface)
• Package
• Module
• Import
• Documentation
• Random number generation
• Method
• Function call
• Dependency

Procedure (50 minutes)

Opening (8 minutes)

1. Review and Connection (3 minutes)

   • Review function design and documentation from previous lesson
   • Connect to today's focus on using existing libraries and APIs

2. Warm-up Activity (5 minutes)

   • Present a complex task (e.g., creating a graph, generating random numbers)
   • Ask students how long they think it would take to code this from scratch
   • Introduce the concept of leveraging existing code through libraries

Main Activities (32 minutes)

3. Lecture: Using Existing Libraries and APIs (12 minutes)

   • Define libraries as collections of pre-written code that can be reused
   • Explain the benefits of using libraries:
     • Saves development time
     • Provides tested, reliable functionality
     • Enables complex features without understanding all details
     • Promotes code reuse and standardization
   • Introduce APIs as specifications for how to use library procedures
   • Discuss different types of libraries:
     • Standard libraries (built into the language)
     • Third-party libraries
     • Custom libraries
   • Explain how to use libraries in programs:
     • Importing/including libraries
     • Reading documentation
     • Calling library functions
     • Handling return values
   • Focus on the RANDOM function as an example:
     • Syntax: RANDOM(a, b)
     • Purpose: generating random integers
     • How randomness is used in programs

4. Demo: Incorporating Library Functions in Programs (8 minutes)

   • Walk through examples of using library functions:
     • Generating random numbers for games or simulations
     • Using math libraries for complex calculations
     • Utilizing string processing libraries
     • Working with data structure libraries
   • Show how to read and interpret API documentation
   • Demonstrate how to use library functions with different parameters
   • Show examples of combining multiple library functions
   • Highlight the importance of understanding function specifications

5. Hands-on: Exploring Available Libraries (12 minutes)

   • Students work in the programming environment
   • Guide students through exploring available libraries
   • Have students experiment with different library functions
   • Students create programs that use library functions for tasks like:
     • Creating a random number guessing game
     • Implementing a simple simulation
     • Performing complex mathematical operations
     • Processing and formatting data
   • Encourage students to consult documentation to understand function usage

Closing (10 minutes)

6. Activity: Solving Problems Using Appropriate Libraries (5 minutes)

   • Present students with several programming problems
   • Students identify which library functions would be useful for each problem
   • Students implement a solution for one problem using library functions
   • Share and discuss different approaches
   • Highlight how libraries simplified the solutions

7. Exit Ticket and Preview (5 minutes)

   • Students create a program that effectively uses library functions
   • Preview that next class will focus on program development with functions

Assessment

• Formative: Quality of library exploration and usage during hands-on activities
• Exit Ticket: Effectiveness of library function usage in the program

Differentiation

For Advanced Students

• Challenge them to combine multiple library functions in sophisticated ways
• Introduce more complex libraries or APIs
• Have them create documentation for a custom library

For Struggling Students

• Provide guided examples of library function usage
• Focus on a smaller set of well-documented library functions
• Offer templates for incorporating library functions

Homework/Extension

• Complete a worksheet with library function exercises
• Research a specialized library and create a program that uses it
• Create a reference guide for commonly used library functions

Teacher Notes

• Emphasize that professional programmers regularly use libraries
• Watch for confusion about which functions are built-in vs. from libraries
• Make connections to real-world software development practices
• Consider discussing open-source libraries and community contributions
• Remind students that understanding API documentation is a critical skill