不带库的Javascript defaultdict

class DefaultDict {
  constructor(defaultFactory) {
    this.defaultFactory = defaultFactory;
    this.items = {};
  }

  get(key) {
    if (!(key in this.items)) {
      this.items[key] = this.defaultFactory();
    }
    return this.items[key];
  }

  set(key, value) {
    this.items[key] = value;
  }

  has(key) {
    return key in this.items;
  }

  delete(key) {
    delete this.items[key];
  }
}

const defaultdict = new DefaultDict(() => []);

defaultdict.get('fruits').push('apple');
defaultdict.get('fruits').push('banana');

console.log(defaultdict.get('fruits')); // 输出: ['apple', 'banana']

defaultdict.set('fruits', ['orange']);
console.log(defaultdict.get('fruits')); // 输出: ['orange']

console.log(defaultdict.has('fruits')); // 输出: true
defaultdict.delete('fruits');
console.log(defaultdict.has('fruits')); // 输出: false

const defaultdict = new DefaultDict(() => ({}));

defaultdict.get('config').key = 'value';
console.log(defaultdict.get('config')); // 输出: { key: 'value' }

defaultdict.get('anotherConfig').key = 'anotherValue';
console.log(defaultdict.get('anotherConfig')); // 输出: { key: 'anotherValue' }