在JavaScript中获取2个对象数组之间的差异[重复]

Question

我在互联网上搜索了很多，我认为这将是一个非常简单的任务，但我没有找到任何解决方案

这是我的两个对象数组

第一个数组

[ 
  { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 },
  { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 },
  { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 },
  { id: 5, fees: 3000, name: 'Four Months Plan', cycle: 4 },
  { id: 181, fees: 4000, name: 'Five Months Plan', cycle: 5 },
  { id: 182, fees: 5000, name: 'Six Months Plan', cycle: 6 },
  { id: 183, fees: 6000, name: 'Seven Months Plan', cycle: 7 } 
] 

第二个数组

[ 
  { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 },
  { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 },
  { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 } 
]

我想得到两个对象数组之间的差异，我想要这样的结果

第一个数组 - 第二个数组 =（第一个数组中存在但第二个数组中不存在的对象数组）

[ { id: 5, fees: 3000, name: 'Four Months Plan', cycle: 4 },
  { id: 181, fees: 4000, name: 'Five Months Plan', cycle: 5 },
  { id: 182, fees: 5000, name: 'Six Months Plan', cycle: 6 },
  { id: 183, fees: 6000, name: 'Seven Months Plan', cycle: 7 } ]

我尝试了很多方法，比如像这样的过滤器

     let c = existingBillPlans.filter(item => 
!billPlans.some(other => item.x == other.x));

但它给出的是空数组。无法理解我应该做什么。

Answer 1

你快到了，使用id而不是x

existingBillPlans.filter(item => !billPlans.some(other => item.id == other.id));

演示

var existingBillPlans = [{
    id: 2,
    fees: 10000,
    name: 'Yearly Plan',
    cycle: 12
  },
  {
    id: 3,
    fees: 1500,
    name: 'Two Months Plan',
    cycle: 2
  },
  {
    id: 4,
    fees: 2500,
    name: 'Three Months Plan',
    cycle: 3
  },
  {
    id: 5,
    fees: 3000,
    name: 'Four Months Plan',
    cycle: 4
  },
  {
    id: 181,
    fees: 4000,
    name: 'Five Months Plan',
    cycle: 5
  },
  {
    id: 182,
    fees: 5000,
    name: 'Six Months Plan',
    cycle: 6
  },
  {
    id: 183,
    fees: 6000,
    name: 'Seven Months Plan',
    cycle: 7
  }
]
var billPlans = [{
    id: 2,
    fees: 10000,
    name: 'Yearly Plan',
    cycle: 12
  },
  {
    id: 3,
    fees: 1500,
    name: 'Two Months Plan',
    cycle: 2
  },
  {
    id: 4,
    fees: 2500,
    name: 'Three Months Plan',
    cycle: 3
  }
]
var output = existingBillPlans.filter(item => !billPlans.some(other => item.id == other.id));

console.log(output);

Answer 2

我想你想检查每个对象的属性。

要检查所有对象的属性，请使用every 方法。

let first_array = [ { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 }, { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 }, { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 }, { id: 5, fees: 3000, name: 'Four Months Plan', cycle: 4 }, { id: 181, fees: 4000, name: 'Five Months Plan', cycle: 5 }, { id: 182, fees: 5000, name: 'Six Months Plan', cycle: 6 }, { id: 183, fees: 6000, name: 'Seven Months Plan', cycle: 7 } ], second_array = [ { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 }, { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 }, { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 } ] 
  
let result = first_array
              .filter(item => !second_array
                          .find(other => Object.keys(other)
                          .every(prop => item[prop] == other[prop]))
              );
console.log(result);

Answer 3

您可以使用.map() 创建一个ids 数组，然后应用.filter()

let result = (
  (array, ids) => array.filter(({ id }) => !ids.includes(id)))(a1, a2.map(({ id }) => id)
);

演示：

let a1 = [ { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 }, { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 }, { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 }, { id: 5, fees: 3000, name: 'Four Months Plan', cycle: 4 }, { id: 181, fees: 4000, name: 'Five Months Plan', cycle: 5 },{ id: 182, fees: 5000, name: 'Six Months Plan', cycle: 6 },{ id: 183, fees: 6000, name: 'Seven Months Plan', cycle: 7 } ];
  
let a2 = [ { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 }, { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 }, { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 } ];
  
let result = (
  (array, ids) => array.filter(({ id }) => !ids.includes(id)))(a1, a2.map(({ id }) => id)
);

console.log(result);

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---

您也可以像这样使用filter()：

let result = a1.filter(({ id }) => !a2.find(o => o.id == id));

演示：

let a1 = [ { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 },{ id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 }, { id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 }, { id: 5, fees: 3000, name: 'Four Months Plan', cycle: 4 }, { id: 181, fees: 4000, name: 'Five Months Plan', cycle: 5 },{ id: 182, fees: 5000, name: 'Six Months Plan', cycle: 6 }, { id: 183, fees: 6000, name: 'Seven Months Plan', cycle: 7 } ];
  
let a2 = [ { id: 2, fees: 10000, name: 'Yearly Plan', cycle: 12 }, { id: 3, fees: 1500, name: 'Two Months Plan', cycle: 2 },{ id: 4, fees: 2500, name: 'Three Months Plan', cycle: 3 } ];
  
let result = a1.filter(({ id }) => !a2.find(o => o.id == id));

console.log(result);

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