Question

我在数组中有下面的对象

[
    {
        "event":"a",
        "count":0
    },
    {
        "event":"b",
        "count":0
    },
    {
        "event":"c",
        "count":0
    }
]

我需要检查count的所有值是否均为零。

我尝试了以下代码

Object.values(alarmTypeCount).every(count => count === 0)

每次都返回false

Answer 1

您需要对对象进行解构以获得想要的属性。

var alarmTypeCount = [{ event: "a", count: 0 }, { event: "b", count: 0 }, { event: "c", count: 0 }],
    allCountsZero = Object.values(alarmTypeCount).every(({ count }) => count === 0);

console.log(allCountsZero);

或者带对象的属性。

var alarmTypeCount = [{ event: "a", count: 0 }, { event: "b", count: 0 }, { event: "c", count: 0 }],
    allCountsZero = Object.values(alarmTypeCount).every(o => o.count === 0);

console.log(allCountsZero);

Answer 2

您需要解构“每个”函数的论点

lately_number.txt

Answer 3

首先，数组上的Object.values()是多余的，因为它只会为您提供数组中的元素数组（您的情况下为对象），这正是数组的意义。示例中的count表示数组中的给定对象。您需要像这样访问对象的count属性：

alarmTypeCount.every(obj => obj.count === 0)

或者，您可以通过销毁分配来做到这一点：

alarmTypeCount.every(({count}) => count === 0)

请参见以下示例：

let alarmTypeCount = [{"event":"a", "count":0}, {"event":"b", "count":0}, {"event":"c", "count":0}];

console.log(alarmTypeCount.every(obj => obj.count === 0));

Answer 4

使用public void Pickdateheatdryopen(View view) { String oldDate = "2017-01-29"; System.out.println("Date before Addition: "+oldDate); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); Calendar calender = Calendar.getInstance(); try{ calender.setTime(sdf.parse(oldDate)); }catch(ParseException e){ e.printStackTrace(); } calender.add(Calendar.DATE,21); final int year = calender.get ( Calendar.YEAR ); final int month = calender.get ( Calendar.MONTH ); final int day = calender.get ( Calendar.DAY_OF_MONTH ); datePickerDialog = new DatePickerDialog ( CowActivity.this, new DatePickerDialog.OnDateSetListener () { @Override public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) { inputheatdry.setText ( (dayOfMonth) + "/" + (month+1 ) + "/" + (year) ); // read1 (); } }, year, month, day ); datePickerDialog.show (); }方法有多个选项，下面是一个摘要，其中包括其他人提到的一些选项：

使用every

Array.prototype

使用some

const isAllZeros = alarmTypeCount.every(a => a.count === 0)

使用find

const isAllZeros = !alarmTypeCount.some(a => a.count !== 0)

使用findIndex

const isAllZeros = !alarmTypeCount.find(a => a.count !== 0)

使用filter

const isAllZeros = alarmTypeCount.findIndex(a => a.count !== 0) === -1

Answer 5

您可以使用filter方法进行检查

let array = [
    {
        "event":"a",
        "count":0
    },
    {
        "event":"b",
        "count":0
    },
    {
        "event":"c",
        "count":0
    }
]

let newArray = array.filter((obj)=>{
  return obj.count > 0;
});

if(newArray.length == 0){
  console.log("All the elements are zero");
}else{
  console.log(newArray.length + " elements are non zero");
}

如何检查对象数组中键的所有值是否均为0？

5 个答案: