Menene React.memo ke buƙata kuma yaushe yana ba da sararin jiki a gida?

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Accepted Answer

`React.memo` ya bugi wani saksaki don ya **keɓe sake fasawa lokacin da props ɗin suke kwas-daidai zuwa fasawa na gida**. A miji, yaro ya sake fasawa kowa da kowa locacin da ubanshi ya yi; `memo` yana gida jiya lokacin da props ba su canja ba. ```jsx const Row = React.memo(function Row({ item, onSelect }) { // re-renders only when `item` or `onSelect` reference changes return

onSelect(item.id)}>{item.name}

; }); ``` ## Galibin: yana buƙata jinginar props `memo` yana bugi **kwas** kwatancewa. Idan uban ya gaji jiya abin new/array/aiki kowa da kowa fasawa, kwatancewa ko kola kila lokaci kuma `memo` ba ya bugi abin damma: ```jsx function List({ items }) { // ❌ a NEW function every render → Row's onSelect prop always "changes" return items.map(i => pick(id)} />); } ``` Dubur-sa da`useCallback`: ```jsx const onSelect = useCallback(id => pick(id), []); // same reference across renders return items.map(i => ); ``` ## Lokacin da yana ba da sararin jiki - Saksaki yana **sau-sau** tare da **daidai** props kuma fasawansa ba mai haɗari ba (manyan jari, manyan bishiya). ## Lokacin da ba haka ba - Yawancin saksaki su sannu ne; kwatancewa ta kanta ina da farashi, kuma bugun kome yana tara hadari jiya riba. **Shauki tun gida** tare da React DevTools Profiler, sannan yi ƙwarai manyan wuri — kar ka yi ƙwarai ba mo ba.