如何在js数组映射中声明typescript类型？

Question

我正在尝试使用 js 数组映射函数https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map进行以下映射

x =  state.users.map(({id, firstName, lastName}) => 
    ({id, value: `${firstName} ${lastName}`}));

但是，我收到以下打字稿错误Binding element 'X' implicitly has an any type每个属性Binding element 'X' implicitly has an any type ，例如 id、firstname 等

如果我尝试为属性分配类型，如下所示：

x =  state.users.map(({id: number, firstName: string, lastName: string}) => 
    ({id, value: `${firstName} ${lastName}`}));

这些被分配为值而不是类型。

如何正确地为地图函数中的属性分配类型？

Answer 1

你可以放任何：

x =  state.users.map(({id, firstName, lastName}: any) => 
    ({id, value: `${firstName} ${lastName}`}));

或使用显式类型：

x =  state.users.map(({id, firstName, lastName}: {id: string, firstName: string, lastName: string}) => 
    ({id, value: `${firstName} ${lastName}`}));