Question

感谢任何帮助！我总是upvote btw

所以我有这个成员名单

export const currentMembers= {
  'A1': {
    'memberStartDate': 0,
    'currentContractEndDate': 0,
    'flagged': false,
    'notes': 'Some Notes about member',
    'memberId': 'A1',
  },
  'A2': {
    'memberStartDate': 1454306400000,
    'currentContractEndDate': 1501747600000,
    'notes': 'Some Notes about member',
    'flagged': false,
    'memberId': 'A2',
  },
  'A3': {
    'memberStartDate': 1454306400000,
    'currentContractEndDate': 1502747600000,    
    'notes': 'Some Notes about member',
    'flagged': false,
    'memberId': 'A3',
  },
}

我试图编写一个函数，它会返回相同的列表，但插入的计算值如下：

export const currentMembersModified = {
  'A1': {
    'memberStartDate': 0,
    'currentContractEndDate': 0,
    'daysRemainingInContract': 0,  // calculated from currentMembers object above
    'flagged': false,
    'notes': 'Some Notes about member',
    'memberId': 'A1',
  },
  'A2': {
    'memberStartDate': 1454306400000,
    'currentContractEndDate': 1501747600000,
    'daysRemainingInContract': 123,  // calculated from currentMembers object above
    'notes': 'Some Notes about member',
    'flagged': false,
    'memberId': 'A2',
  },
  'A3': {
    'memberStartDate': 1454306400000,
    'currentContractEndDate': 1502747600000,
    'daysRemainingInContract': 234, // calculated from currentMembers object above
    'notes': 'Some Notes about member',
    'flagged': false,
    'memberId': 'A3',
  },
}

我一直在尝试：

const modifiedMembers = Object.keys(currentMembers).forEach(key => {
  const currentMemberObject = currentMembers[key]

  const currentDate = new Date()
  const currentEndDate = currentMembers[key].currentContractEndDate
  const calculatedDateStuff = currentEndDate - currentDate

  return {stuff I don't know how to do}
})

谢谢！

Answer 1

这是一个解决方案，但如果您想保留currentMembers的原始副本，请使用Object.assign()或ES6点差运算符制作副本。

for (key in currentMembers) {
  var currentMemberObject = currentMembers[key]

  var currentDate = new Date()
  var currentEndDate = currentMembers[key].currentContractEndDate
  var calculatedDateStuff = currentEndDate - currentDate;
  // fix logic to calculate number of days yourself, however, here is how
  // you need to update those objects
  currentMembers[key]['daysRemainingInContract'] = calculatedDateStuff
}

console.log(currentMembers);

Answer 2

您可以@Norris在How do I get the number of days between two dates in JavaScript? enter image description here使用for..of循环，Object.entries()，Object.assign()方法

const currentMembersModified = new Object;

const currentMembers= {
  'A1': {
    'memberStartDate': 0,
    'currentContractEndDate': 0,
    'flagged': false,
    'notes': 'Some Notes about member',
    'memberId': 'A1',
  },
  'A2': {
    'memberStartDate': 1454306400000,
    'currentContractEndDate': 1501747600000,
    'notes': 'Some Notes about member',
    'flagged': false,
    'memberId': 'A2',
  },
  'A3': {
    'memberStartDate': 1454306400000,
    'currentContractEndDate': 1502747600000,    
    'notes': 'Some Notes about member',
    'flagged': false,
    'memberId': 'A3',
  }
}

for (const [key, prop] of Object.entries(currentMembers)) {

  const {memberStartDate, currentContractEndDate} = prop;  
 
  const [to, from] = [
    // https://stackoverflow.com/a/20082660/
    Math.floor(new Date(currentContractEndDate).getTime() / (3600*24*1000)),
    Math.floor(new Date(memberStartDate).getTime() / (3600*24*1000))
  ];
  
  Object.assign(currentMembersModified
  , {[key]:Object.assign({}, prop, {daysRemainingInContract: to - from})});
  
}

console.log(currentMembersModified);

Answer 3

如果你正在使用babel和你的反应项目，那么根据你所包含的阶段，你可能会尝试这样的事情：

var newMembers; // new object/state
Object.keys(currentMembers).forEach((key) => {
  var calculatedDays = currentMembers[key].currentContractEndDate - 21343214213; // or whatever logic you need here
  var member = {};
  member[key] = {
        ...currentMembers[key],
      calculatedDays
    }
  newMembers = {
    ...newMembers,
    ...member
  }
});

这使用spread运算符组合对象。 ES6目前只允许使用扩展运算符组合迭代，但由于babel将它们与对象一起使用是一种常见的React模式，因为这意味着您可以避免更改原始对象。

迭代对象列表但插入计算值

3 个答案: