javascript - 如何在一行中从单独的解构属性进行解构？

Question

const { navigation, currentScreen, childIndex } = this.state
const screen = navigation[currentScreen]

如何用一行代码而不是两行代码编写此代码？

Answer 1

与{ [currentScreen]: screen } ，确保提取 currentScreen事先:

const state = { navigation: { foo: 'val' }, currentScreen: 'foo' };

const { navigation, currentScreen, childIndex, navigation: { [currentScreen]: screen } } = state
console.log(screen);

也就是说，它确实很难阅读。我强烈建议您使用当前版本。仅在 actually code-golfing 时编写高尔夫球线代码，否则最好在几乎所有情况下优化可读性。

数组示例 navigation而不是对象:

const state = { navigation: ['val1', 'val2', 'val3'], currentScreen: 1 };

const { navigation, currentScreen, childIndex, navigation: { [currentScreen]: screen } } = state
console.log(screen);