feat: add question #56
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BetaSu
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Apr 14, 2022
| 实现水平垂直居中布局 | ||
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| 简述 React.memo 包裹一个组件和 useMemo 缓存一个组件有什么区别？二者是否都可以达到性能优化的效果？如果 useMemo 可以达到性能优化的效果，那么 React.memo 还有意义么？ |
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业务上是可以这样用的，虽然不知道这个还符不符合现在的规范
codesandbox
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我觉得这是个好问题，但是太深入React原理了。 在这里我回答下吧：
两者要达到的目的是相同的，都是为了让React走优化策略，让子组件不render。
区别是：React.memo是改变优化策略的判断条件，将判断props === newProps变为浅比较props与newProps
memo不改变判断条件，只是用比较hack的方式使得props === newProps
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