从Angular中的数组的数组中获取元素

Question

使用Angular-我有一个数组为people[]的json文件，其中数组为phones[]

我想回来

people[index].phones[index].phonenumber

(where people.personid = x and people.phones.phoneid = y) 

任何建议都将受到赞赏

Answer 1

只需在数组上使用filter函数。

let person = people.filter(person => person.personId === x);
let phone = person && person.phones.filter(phone => phone.phoneId === y);

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以下是 Working Example as a Sample StackBlitz 供您参考。

Answer 2

您可以使用过滤器函数来返回过滤后的数组

private filterPhone(x:number,y:number) : number { 
    let phoneNum : number;
    let person = this.people.filter(person => person.personId === x);
    let phone = person.length > 0 && person[0].phones.filter(phone => phone.phoneId === y);
    if(phone.length > 0 && phone[0].phoneNumber){
      phoneNum = phone[0].phoneNumber;
    }
    return phoneNum;
}

或者您可以使用findIndex（）函数来实现此目的。

private findPhoneById(x:any,y:any) : number { 
    let result : number = -1; 
    let personIndx = this.people.findIndex(p => p.personId === x);
    if(personIndx > result){
        let phoneIndx = this.people[personIndx].phones.findIndex(phone => phone.phoneId === y);
        if(phoneIndx > result){
          result = this.people[personIndx].phones[phoneIndx].phoneNumber;
        }
    }
    return result;
}