在JS中调用命名空间中的单例库方法，而不完全限定namespac

Posted 2021-02-26

;(function() {
  MyClass = {
    map: function(object, callback) {
      var items = [];
      each(object, function(i) { items.push(callback.apply(this, arguments)); });
      return items;
    },
 
    each: function(object, callback) {
      for (var i = 0; i < object.length; i++) {
        callback(i);
      }
    }
  }
 
  var methods = 'each map'.split(/ /);
  while (methods.length) { eval('var ' + methods[0] + ' = MyClass.' + methods.shift()); }
})();
 
// Map can refer to each without dereferencing
result = MyClass.map([1, 2, 3], function(i) {
  return i + 1;
});
 
print(result);
// 1,2,3