Unhandled JS Exception: TypeError: (0 , _react.useMemo) is not a function 检查了项目内容发现没有异常,对比之前的项目中发现 react-redux版本是^7.1.1 老版本是^5.0.7 通过对react-redux降级到^5.0.7解决该问题。 附其它版本对比 "react": "16.3.1", "react-native": "0.55.4", "react-native-i18...
在函数handleCheckSession示例之后以其他顺序执行useMemo：
编译可以通过,但是运行会报错:TypeError: getNum is not a function看了好久没发现错在哪里。。。求指点一下哈import React, {useState, useMemo} from 'react'; function Example() { const [count, setCount] = useState(1); const [val, setValue] = useState...
React.memo()is a higher-order component that we can use to wrap components that we do not want to re-render unless props within them change useMemo()is a React Hook that we can use to wrap functions within a component. We can use this to ensure that the values within that function ar...
When Not to Use the useMemo React Hook? Conclusion Learn all about React through this React JS Course video: What is useMemo? useMemo is a function provided by React, a popular JavaScript library for building user interfaces. It is used to optimize performance by memoizing the result of a ...
What's happening here is that in the first useMemo(), the body is a function call which we memoize. For the second useMemo(), the body is an addition expression which we know produces a number. Numbers don't need to be memoized since they can be compared with ===, so we prune ...
It is not recommended to use memoization in the following cases: When the resulting value (expression or variable) is primitive (string, number, boolean). Incorrect functionComponent(){constwidth=useMemo(()=>someValue*10,[]);// results in integer, wouldn't break hooks' shallow comparison; Me...
Wrapping the function in useCallback() ensures the function is not recreated, so useEffect() is not triggered to run again. When to use useMemo() If a function includes a complex calculation, you can avoid recomputing it by using the useMemo() hook. This hook returns a memoized value ...
However, using it when it is not needed can actually slow down your application instead. 1. Trivial computations If the function you are wrapping with useMemo is a simple computation, then the cost of using useMemo can be more consequential. ...
In this example, the handleClick function is memoized using useCallback. As a result, the MemoizedListItem components do not re-render when their parent component (ItemList) re-renders, unless the handleClick function changes, which, in this case, never happens....