Chapter 4 - Working with Tables

Table of Contents

Working with Tables - 43

• Storing Data Using Tables - 43
  • Creating and Indexing Tables - 44
  • Clearing an Element from a Table - 44
  • Shortcuts for String Keys - 45
  • Creating Populated Tables - 45
• Using Tables as Arrays - 46
  • Creating an Array - 46
  • Getting the Length of an Array - 47
  • Adding Elements to an Array - 48
  • Removing Elements from an Array - 49
  • Sorting the Elements of an Array - 50
• Using Tables as Namespaces - 51
  • Creating a util Namespace - 51
  • Adding Functions to util - 51
    • Storing an Existing Function - 51
    • Defining a New Function - 52
• Object Oriented Programming with Tables - 52
  • Creating a Non-Object-Oriented Counter - 53
  • Using Tables as Simple Objects - 53
  • Using : to Call Object Methods - 54
  • Defining Functions Using : - 54
  • Making a Better Counter - 55
• Extending Tables with Metatables - 56
  • Adding a Metatable - 56
  • Defining Metamethods - 57
    • Defining Basic Arithmetic using __add, __sub, __mul, and __div - 58
    • Defining Negation using __unm - 59
    • Creating Meaningful Output with __tostring - 59
    • Concatenating Tables Using __concat - 60
    • Exploring Fallback Tables with __index - 60
    • Catching New Keys with __newindex - 62
  • Bypassing Metatables - 63
    • value = rawget(tbl, key) - 63
    • rawset(tbl, key, value) - 63
• Summary - 63