我有一个包含对象数组的对象。
obj = {};
obj.arr = new Array();
obj.arr.push({place:"here",name:"stuff"});
obj.arr.push({place:"there",name:"morestuff"});
obj.arr.push({place:"there",name:"morestuff"});
我想知道从数组中删除重复对象的最佳方法是什么。例如,obj.arr将变成。。。
{place:"here",name:"stuff"},
{place:"there",name:"morestuff"}
您还可以创建一个通用函数,该函数将根据传递给该函数的对象键过滤数组
function getUnique(arr, comp) {
return arr
.map(e => e[comp])
.map((e, i, final) => final.indexOf(e) === i && i) // store the keys of the unique objects
.filter(e => arr[e]).map(e => arr[e]); // eliminate the dead keys & store unique objects
}
你可以这样调用函数,
getUnique(things.thing,'name') // to filter on basis of name
getUnique(things.thing,'place') // to filter on basis of place
另一种方法是使用reduce函数,并使用一个新数组作为累加器。如果累加器数组中已经有一个同名的对象,那么不要将其添加到那里。
let list = things.thing;
list = list.reduce((accumulator, thing) => {
if (!accumulator.filter((duplicate) => thing.name === duplicate.name)[0]) {
accumulator.push(thing);
}
return accumulator;
}, []);
thing.things = list;
我添加了这个答案,因为我找不到与InternetExplorer11兼容的好的、可读的es6解决方案(我使用babel来处理箭头函数)。问题是IE11没有没有polyfill的Map.values()或Set.values)。出于同样的原因,我使用filter()[0]来获取第一个元素,而不是find()。
const uniqueElements = (arr, fn) => arr.reduce((acc, v) => {
if (!acc.some(x => fn(v, x))) { acc.push(v); }
return acc;
}, []);
const stuff = [
{place:"here",name:"stuff"},
{place:"there",name:"morestuff"},
{place:"there",name:"morestuff"},
];
const unique = uniqueElements(stuff, (a,b) => a.place === b.place && a.name === b.name );
//console.log( unique );
[{
"place": "here",
"name": "stuff"
},
{
"place": "there",
"name": "morestuff"
}]
考虑lodash.uniqWith
const objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];
_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
来源
JSFiddle公司
这将在不传递任何键的情况下删除重复对象。
uniqueArray=a=>[…new Set(.map(o=>JSON.stringify(o))].map(s=>JSON.parse(s));var objects=[{'x':1,'y':2},{'x':2,'y':1},{'x':1,'y':2}];var unique=uniqueArray(对象);console.log(“原始对象”,对象);console.log(“唯一”,唯一);
uniqueArray = a => [...new Set(a.map(o => JSON.stringify(o)))].map(s => JSON.parse(s));
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];
var unique = uniqueArray(objects);
console.log(objects);
console.log(unique);