js数组及数组对象取并集、交集、差集

数组区交集

let a=new Set([1,2,3,4,5]); 
let b=new Set([1,2,3,4,5,6,7,8,9]); 
let arr = Array.from(new Set([...a, ...b])); 
console.log('arr',arr);

数组取并集

let a=new Set([1,2,3,4,5]);
let b=new Set([1,2,3,4,5,6,7,8,9]);
let arr = Array.from(new Set([...b].filter(x => a.has(x))));

数组对象取交集

 let a=[{id:1,a:123,b:1234},{id:2,a:123,b:1234}];
 let b=[{id:1,a:123,b:1234},{id:2,a:123,b:1234},{id:3,a:123,b:1234},{id:4,a:123,b:1234}];
 let arr = [...b].filter(x => [...a].some(y => y.id === x.id));
 console.log('arr',arr)

数组对象取差集

let a=[{id:1,a:123,b:1234},{id:2,a:123,b:1234}];
let b=[{id:1,a:123,b:1234},{id:2,a:123,b:1234},{id:3,a:123,b:1234},{id:4,a:123,b:1234}];
let arr = [...b].filter(x => [...a].every(y => y.id !== x.id));
console.log('arr',arr);