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[英]How to Define Object type that contains properties as number in Typescript
[英]How to define type of an object whose properties are going to be fetched from an array in TypeScript
如何定義 object 的類型,其屬性將從 TypeScript 中的數組中獲取。
在以下示例中,如何定義lookUpMap object 的類型?
const arr1 = ["a", "b", "c", "d"];
const arr2 = ["x", "y", "b"];
class Arr {
private lookUpMap = {}
constructor(private arr1: string[], private arr2: string[]){}
linearCompare(){
for(let i of this.arr1){
this.lookUpMap[i] = true
}
for(let i of this.arr2){
if(this.lookUpMap[i]){
return console.log(true);
}
}
return console.log(false);
}
}
const arrComp = new Arr(arr1, arr2);
arrComp.linearCompare()
謝謝
對於lookupMap
,我能想到的最直接的類型是類似於字典的object,其屬性類型為true | undefined
字符串索引簽名。 true | undefined
:
private lookUpMap: { [k: string]: true | undefined } = {}
這將允許您將true
寫入任何字符串值的鍵,如this.lookUpMap[i] = true
,並了解當您從字符串值的鍵讀取時,結果將為true
或undefined
,如if (this.lookupMap[i]) {...}
。
請注意,這與您的密鑰來自 arrays 的事實無關; lookupMap
將允許您使用任何string
對其進行索引。
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