enum - enumeration

• It's an object that stores related values
• The goal of enum is to signal to other engineers about a property
• The options are stored in capital first letter
• Enum is used to represent a fixed known set of options

// Enumeration of MatchResults
enum MatchResult {
  HomeWin = 'H',
  AwayWin = 'A',
  Draw = 'D'
}

let win = 0;
let lose = 0;
for (let match of matches) {
  if (MatchResult.HomeWin) win++;
  else lose++:
}

// Type assertion
let match_result as MatchResult // consider match_result as one of the possible values of MatchResult
// Only accepts 'H', 'A' or 'D'
let match: MatchResult