我想要新的数组2数组不等于数据

Question

我想要新的数组2数组不等于数据<<em>例子/em>

let a = [{id:1, name:"a"},{id:2, name:"b"},{id:3, name:"c"}];
let b = [{id:1, name:"a"},{id:2, name:"b"},{id:3, name:"c"}, {id:4, name:"d"}];

结果

c = [{id:4, name:'d'}]

Answer 1

您可以使用filter()和includes()函数来完成此操作。

let a = [{id:1, name:"a"},{id:2, name:"b"},{id:3, name:"c"}];
let b = [{id:1, name:"a"},{id:2, name:"b"},{id:3, name:"c"}, {id:4, name:"d"}];
// b diff a
let resultA = b.filter(elm => !a.map(elm => JSON.stringify(elm)).includes(JSON.stringify(elm)));
// a diff b
let resultB = a.filter(elm => !b.map(elm => JSON.stringify(elm)).includes(JSON.stringify(elm)));  
// show merge 
console.log([...resultA, ...resultB]);

Answer 2

const a = [{id:1, name:"a"},{id:2, name:"b"},{id:3, name:"c"}]
const b = [{id:1, name:"a"},{id:2, name:"b"},{id:3, name:"c"}, {id:4, name:"d"}]
const bId = b.map(item => item.id)
const result = a.filter(item => bId.includes(item.id))
console.log(result)

Answer 3

也许你正在寻找set，看看:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set