先来看一个问题: 如何理解Array.apply(null, {length:5})的{length:5}? 我测试过Array.apply(null, {length:5}) //返回[undefined, undefined, undefined, undefined, undefined] Array.apply(null, [{length:5}])和Array({length:5})返回的结果是一样的,为[[object Object] { length: 5 }] 第二.三还能理解!…