X_NNNNN

领取 [ 响应式 ] 计算属性与侦听器 src/guide/reactivity-computed-watchers.md

领取 [ 响应式 ] 响应式原理 src/guide/reactivity-fundamentals.md

let a = {1:222, 2:123, 5:888} let b = [] for (var i = 1; i < 13 ;i++) { if(a[i] !== undefined) { b.push(a[i]) } else { b.push(null) }...

完了，难到我了，不能用爱发电了