javascript - 如何通过其子数组对象属性计算父数组的项数

Question

假设我有一组人员，其中有很多办公室。

var personnel = [
  {
    id: 1,
    name: 'John Doe',
    offices: [
      {
        id: 1,
        name: 'Office 1',
        isAssigned: false
      },
      {
        id: 2,
        name: 'Office 2',
        isAssigned: true
      },
      {
        id: 3,
        name: 'Office 3',
        isAssigned: false
      }
    ]
  },{
    id: 2,
    name: 'Jerry Smith',
    offices: [
      {
        id: 2,
        name: 'Office 2',
        isAssigned: true,
      },
      {
        id: 3,
        name: 'Office 3',
        isAssigned: false,
      }
    ]
  }
]

我如何获得分配到特定办公室的人员数量？或者在 office 2 中分配了多少？结果:2

Answer 1

这里是解构参数的版本:

personnel.filter( ({offices}) => 
    offices.some( ({name, isAssigned}) => isAssigned && name === office) 
).length

function countInOffice(personnel, office) {
    return personnel.filter( ({offices}) => 
        offices.some( ({name, isAssigned}) => isAssigned && name === office) 
    ).length
}

var personnel = [
  {
    id: 1,
    name: 'John Doe',
    offices: [
      {
        id: 1,
        name: 'Office 1',
        isAssigned: false
      },
      {
        id: 2,
        name: 'Office 2',
        isAssigned: true
      },
      {
        id: 3,
        name: 'Office 3',
        isAssigned: false
      }
    ]
  },{
    id: 2,
    name: 'Jerry Smith',
    offices: [
      {
        id: 2,
        name: 'Office 2',
        isAssigned: true,
      },
      {
        id: 3,
        name: 'Office 3',
        isAssigned: false,
      }
    ]
  }
];

var count = countInOffice(personnel, 'Office 2');

console.log(count);