当typescript编写代码时出现这个报错怎么办？
例如如下代码及声明
interface IJobData {generation?: {id: number; name: string; code: string;}[]publishing?: {id: number; name: string; code:string;}[]}const method = ['generation', 'publishing']const originJobData = {generation: [{id: 1, name: 'generation', code: 'test1'},{id: 2, name: 'test2', code: 'test2' }],publishing: [{id: 3, name: 'publish', code: 'test3'},{id: 4, name: 'publish11', code: 'test4'},]}const formatJobData: IJobData = {}method.forEach((method:string)=>{if (originJobData[method]) formatJobData[method] = originJobData[method]})// 此时会报如下错误Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'IJobData'.No index signature with a parameter of type 'string' was found on type 'IJobData'
又比如：
const str = 'name' as string;const obj = {name: 'James Doe',country: 'Chile',};// ⛔️ Error: Element implicitly has an 'any' type// because expression of type 'string' can't be used// to index type '{ name: string; }'.// No index signature with a parameter of type 'string'// was found on type '{ name: string; }'.ts(7053)obj[str];
当我们尝试通过对象的属性访问对象的value时，就会报这个错误；遇到这种问题我们如何解决呢？
第一个解决方案：
const str = 'name' as string;const obj = {name: 'James Doe',country: 'Chile',};// 👇️ "James Doe"console.log(obj[str as keyof typeof obj]);// 👇️ type T = "name" | "country"type T = keyof typeof obj;
第二种解决方案：
const str = 'name' as string;interface Person {name: string;country: string;}const obj: Person = {name: 'James Doe',country: 'Chile',};console.log(obj[str as keyof Person]); // 👉️ "James Doe"// 👇️ type T = "name" | "country"type T = keyof Person;
第三种解决方案
interface Person {name: string;country: string;}// 👇️ this will only ever be one of object's keysconst str: keyof Person = 'name';const obj: Person = {name: 'James Doe',country: 'Chile',};console.log(obj[str]); // 👉️ "James Doe"
