A Memoization Pattern - JavaScript Patterns

gistfile1.txt

var myFunc = function (param) {
  if (!myFunc.cache[param]) {
    var result = {};

    // ... expensive operation ... 

    myFunc.cache[param] = result;
  }

  return myFunc.cache[param];
};

// cache storage 
myFunc.cache = {};

//slightly different example
var memoize = function(fn) {
  var cache = {};
  return function(arg) {
    if (arg in cache) return cache[arg];
    cache[arg] = fn(arg);
    return cache[arg];
  };
}