如何使用setState插入React的状态数组? [英] How can I insert into React's state array with setState?

问题描述

我希望在react中进行修改和排列，并在特定索引上插入元素.这是我的状态:

I'm looking to modify and array in react and insert elements on specific index. This is how my state looks like:

this.state = {arr: ['', '', '', '' ]}

我想做的是编译此arr[index] = 'random element'以响应js setState语法.我想做的是:

What I wanna do is to compile this arr[index] = 'random element' to react js setState syntax. What I tried to do was:

this.setState({ arr[index]: 'random element' })

但是失败了，ty！

推荐答案

使用slice()克隆当前状态.这样，原始状态将保持不受影响，直到setState().克隆后，对克隆的阵列进行操作并将其设置为状态.先前的答案将变异状态.在此处阅读有关内容

Clone the current state using slice(). By doing this, the original state remains unaffected till setState(). After cloning, do your operations over the cloned array and set it in the state. The previous answer will mutate the state. Read about this here

let a = this.state.arr.slice(); //creates the clone of the state
a[index] = "random element";
this.setState({arr: a});

这篇关于如何使用setState插入React的状态数组?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！