Javascript reduce，无法处理对象数组

Question

我正在尝试在一个对象数组上处理这个规则 如果有一个或多个类型等于固定电话的对象返回第一个数字，如果没有带有type = landline的对象，则返回第一个数字只有当它的type属性不同于mobile时，如果它等于mobile返回下一个数字如果可用，否则返回空白值

var phoneObject = [
  {
    type: 'mobile',
    phone: '0123456789'
  },
  {
    type: 'mobile',
    number:'78945610'
  }
  {
    type:'landline'
    number:'15975345'
  }
];

var number = phoneObject.reduce((a,b)=>{
  if (a.type === 'landline' && b.type === 'landline') {
    b.number = a.number;
  }
  else {
    if (a.type !== 'landline' && b.type !== 'landline') {
      if (a.type !== 'mobile') {
        b.number = a.number;
      } else {
        if (b.number) {
          return b.number;
        }
        else {
          b.number = '';
        }
      }
    }
  }
  return b.number;
});
console.log(number);

// should return the third number for this array
var phoneObject = [
  {
    type: 'mobile',
    phone: '0123456789'
  },
  {
    type: 'mobile',
    number:'78945610'
  }
  {
    type:'landline'
    number:'15975345'
  }
];


// for this one it should return the first 
var phoneObject = [
  {
    type: 'landline',
    phone: '0123456789'
  },
  {
    type: 'mobile',
    number:'78945610'
  }
  {
    type:'landline'
    number:'15975345'
  }
];

// for this one it should return the second number
  {
    type: 'mobile',
    phone: '0123456789'
  },
  {
    type: 'mobile',
    number:'78945610'
  }
];

// and for this last one it should return a blank value
var phoneObject = [
  {
    type: 'mobile',
    phone: '0123456789'
  },
];

感谢您的帮助 最好的祝福， 萨拉

Answer 1

这个评论太长了，但是......

你忘了两个逗号：

 {
type: 'mobile',
number:'78945610'
}
{
type:'landline'
number:'15975345'
}

必须编辑为：

 {
type: 'mobile',
number:'78945610'
},
{
type:'landline',
number:'15975345'
}

Answer 2

你可以做一些体面的检查并保存第二个号码。仅在没有固定电话号码的情况下使用它。

此提案适用于Array#reduce。

＆＃13;

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library(dplyr)

df <- mtcars %>% group_by(cyl, mpg)

groups(df)

[[1]]
cyl

[[2]]
mpg

＆＃13;

＆＃13;

＆＃13;

与上述相同，但Array#some

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function getNumber(array) {
    var counter = 0,
        second = '';
    return array.reduce(function (r, o) {
        if (r) {
            return r;
        }
        if (o.type === 'landline') {
            return o.number;
        }
        counter++;
        if (counter === 2) {
            second = o.number;
        }
    }, '') || second;
}

//should return the third number for this array
var phoneObject1 = [{ type: 'mobile',  number: '0123456789' }, { type: 'mobile', number:'78945610' }, { type: 'landline', number:'15975345' }];

// for this one it should return the first 
var phoneObject2 = [{ type: 'landline', number: '0123456789' }, { type: 'mobile', number:'78945610' }, { type:'landline', number:'15975345' }];

// for this one it should return the second number
var phoneObject3 = [{ type: 'mobile', number: '0123456789' }, { type: 'mobile', number:'78945610' }];

//and for this last one it should return a blank value
var phoneObject4 = [{ type: 'mobile', number: '0123456789' }];

console.log([phoneObject1, phoneObject2, phoneObject3, phoneObject4].map(getNumber));

＆＃13;

＆＃13;

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