属性"长度"的类型是不兼容的.类型"4"不能分配给"1"类型

Question

我现在正在学习打字稿/角度,并且无法解决为什么TSLint将此作为错误抛出,但是代码本身可以在浏览器中工作和显示.

export class GreetingComponent implements OnInit {

  names: [{ name: string }] = [{ name: 'Tom' }, { name: 'Dave' }, { name: 'Katie' }, { name: 'John' }];
  constructor() { }

  ngOnInit() {
  }

特别是这条线:

 names: [{ name: string }] = [{ name: 'Tom' }, { name: 'Dave' }, { name: 'Katie' }, { name: 'John' }];

完全错误:

[ts]
Type '[{ name: string; }, { name: string; }, { name: string; }, { name: string; }]' is not assignable to type '[{ name: string; }]'.
  Types of property 'length' are incompatible.
    Type '4' is not assignable to type '1'.
(property) GreetingComponent.names: [{
        name: string;
    }]

Answer 1

类型:

[{name: string}]

是一个元素的元组类型.所以该类型只能是一个包含单个项目的数组.如果您希望该类型是一个填充了这些对象的任何长度的数组,那么它将被写为

{name: string}[]

// Or if you prefer:

Array<{name: string}>