variables

Variables

Make Variable Declarations Easy

• Dont use implicit declarations
• Use naming conventions
• Cross reference variable names

Variable Scope

• Keep declarations and their references close together
  • Short number of lines between uses
• Keep variables "live" for as short a time as possible
  • Good for minimizing complexity
  • Makes splitting into rouintes easy

Naming Variables

• Name shouldn't be cute or sounds good
  • The variable and its name should be the same thing
• Name fully and accurately describes the entity the variable represents
• Speak to the problem, not the solution
  • Express the WHAT, not thw how
• Proper length is about 2-3 words without connectors
• Computed value operations go at end of name
  • Total, sum, max, min, record, string
  • revenueTotal() expenseAverage
  • Instead of num use count, total, index
• Use common opposites
  • Begin/end
  • Up/down
  • Full list

Naming Conventions

Why naming conventions

• Help you learn code more quickly on a project
  • Dont have to keep track of:
    • What Johns code looks like
    • What Claires code looks like
    • Anyone else on project
• Without conventions, can easily call the same thing two different names
  • pointsTotal vs totalPoints
  • This is mega confusing
• Emphasize relationships among related items

Any convention is better than no convention - no matter how arbitrary it is

Naming Specific Data Types

Names to Avoid

• Avoid misleading names or abbreviations
• Avoid names with similar meanings
  • If you can switch the names of two variables without hurting the program, then both need to be renamed
• Avoid variables with different meanings but similar names
  • clientRecs vs clientReps
  • Look similar but very different values
• Avoid names that sound familliar
  • rap and wrap
• Avoid numbers in names
  • file1, file2, etc
  • If the numbers really are important, use an array instead of spearate values
• Avoid words that are commonly misspelled in english
• Dont differentiate variable name solely by capitalization