Javascript 理解{[name:string]:}在Typescript中的用法
在我们的应用程序中,我们有这些代码Javascript 理解{[name:string]:}在Typescript中的用法,javascript,typescript,Javascript,Typescript,在我们的应用程序中,我们有这些代码 export function compose<T>( initial: T, tasks: { [name: string]: (state: T, payload?: any) => void }, copy = CopyStrategy.json ) { return (state: T = initial || <T>{}, action: any) => { let
export function compose<T>(
initial: T,
tasks: { [name: string]: (state: T, payload?: any) => void },
copy = CopyStrategy.json
) {
return (state: T = initial || <T>{}, action: any) => {
let reply = null;
const task = tasks[action.type];
if (task) { task(reply, action.payload); }
return reply;
};
}
导出函数组合(
首字母:T,
任务:{[name:string]:(状态:T,有效负载?:any)=>void},
copy=CopyStrategy.json
) {
返回(状态:T=initial |{},操作:any)=>{
让reply=null;
const task=tasks[action.type];
if(task){task(reply,action.payload);}
回复;
};
}
这就是它的用途
export const timeSheetReducer = compose<TimeSheetState>(timeSheetInitial, {
['timehsheet']: (state, payload) => {
....
},
['timehsheetSetStatus']: (state, payload) => {
....
}
},
export const timesheetducer=compose(timeSheetInitial{
['timehsheet']:(状态、有效负载)=>{
....
},
['timehsheetSetStatus']:(状态、有效负载)=>{
....
}
},
我不理解这部分任务:{[name:string]:(state:t,payload?:any)=>void},在ES2015中,
[
和]
意味着什么,在它的用法中,这是计算属性的语法:
let key = 'mykey';
let obj = { [key]: 'myvalue' }; // computed property
console.log(obj.mykey); //=> 'myvalue'
如果要在TypeScript中键入,除了使用以下类型外,还应使用相同的语法:
let obj: { [key: string]: string } = { [key]: 'myvalue' };
这告诉我们,obj
是一个以字符串作为键、字符串作为值的对象