#author("2022-07-25T01:14:45+09:00","","") [[Javascript/デザインパターン]] * Javascript/デザインパターン/GoF/Singleton [#k2862433] let instance; class MySingleton { constructor() { if (!instance) { this.val = 10; instance = this; } return instance; } } var c1 = new MySingleton(); var c2 = new MySingleton(); c1.val = 10; c2.val = 20; console.log(c1.val); // 20