Understanding Code

Last Week

Why Coding?

• Code replicates processing steps
• Code reduces errors
• Documented code creates a record of processing steps
• Other people’s code = less work!
  • Don’t reinvent
  • Use standard libraries when possible

How Do You Learn Coding?

• Learn the syntax
  • Tutorials
  • Documentation
• Practice
  • Really helps to have specific problem to solve
• Look at examples

Programmers spend more time reading code than writing code

What can cause problems?

• Short term memory
  • Limited to 2-6 items
  • Works better when recognize patterns
• Long term memory
  • Practice
  • Memorization
• Working Memory
  • Tricks

Extraneous Cognitive Load

6 + 8

vs

a = 6
b = 8

z = a + b

Trick 1: Comments

Add human readable (non-executable) annotations within the code

• Document code purpose and design
• Should not need to explain every single step

Trick 2: State Table

Write down the values of variable for each step in the code

x = 12
y = 5
z = y
y = x
x = z

Trick 3: Refactoring

Transform code to “improve” the internal structure without changing the external behavior

• Make a copy and change it
• Replace syntax you don’t understand
• Perhaps revert changes once you figured it out (source control)

Trick 4: Self-Documenting Code

Write code using human-readable names and phrases that reflects the symbols’ meaning

• Descriptive variable names
• Repeated tasks should be functions (with descriptive names)

def swap_values(first_value, second_value):
    holding = second_value
    second_value = first_value
    first_value = holding
    ...

Trick 5: Tell your troubles to a Duck

Or any little toy you have sitting on your desk

Trick 6: Integrated Development Environment (IDE)

Application that provides tools for programming

• Debugging
• Tracking variables
• Syntax checking
• Autocomplete

Let’s Take a Break