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"}
使用ES6“reduce”和“find”数组助手方法的简单解决方案
工作效率高,非常好!
"use strict";
var things = new Object();
things.thing = new Array();
things.thing.push({
place: "here",
name: "stuff"
});
things.thing.push({
place: "there",
name: "morestuff"
});
things.thing.push({
place: "there",
name: "morestuff"
});
// the logic is here
function removeDup(something) {
return something.thing.reduce(function (prev, ele) {
var found = prev.find(function (fele) {
return ele.place === fele.place && ele.name === fele.name;
});
if (!found) {
prev.push(ele);
}
return prev;
}, []);
}
console.log(removeDup(things));
使用ES6“reduce”和“find”数组助手方法的简单解决方案
工作效率高,非常好!
"use strict";
var things = new Object();
things.thing = new Array();
things.thing.push({
place: "here",
name: "stuff"
});
things.thing.push({
place: "there",
name: "morestuff"
});
things.thing.push({
place: "there",
name: "morestuff"
});
// the logic is here
function removeDup(something) {
return something.thing.reduce(function (prev, ele) {
var found = prev.find(function (fele) {
return ele.place === fele.place && ele.name === fele.name;
});
if (!found) {
prev.push(ele);
}
return prev;
}, []);
}
console.log(removeDup(things));
你听说过洛达什图书馆吗?当您不想将逻辑应用于代码时,我建议您使用此实用程序,并使用已优化且可靠的现有代码。
考虑制作一个这样的数组
things.thing.push({place:"utopia",name:"unicorn"});
things.thing.push({place:"jade_palace",name:"po"});
things.thing.push({place:"jade_palace",name:"tigress"});
things.thing.push({place:"utopia",name:"flying_reindeer"});
things.thing.push({place:"panda_village",name:"po"});
注意,如果您想保持一个属性的唯一性,您可以使用lodash库来实现这一点。在这里,您可以使用_.uniqBy
.uniqBy(数组,[iteratee=.identity])
此方法类似于_.uniq(它返回一个数组的无重复版本,其中只保留每个元素的第一次出现),只是它接受iterate,iterate为数组中的每个元素调用,以生成计算唯一性的标准。
因此,例如,如果要返回具有唯一属性“place”的数组
_.uniqBy(things.thing,'place')
同样,如果您希望唯一属性为“name”
_.uniqBy(things.thing,'name')
希望这有帮助。
干杯
如果您可以等到所有添加之后再消除重复项,典型的方法是首先对数组进行排序,然后消除重复项。排序避免了在遍历每个元素时扫描数组的N*N方法。
“消除重复项”函数通常称为unique或uniq。一些现有的实现可以结合这两个步骤,例如原型的uniq
如果你的图书馆还没有,这篇文章没有什么想法可以尝试(还有一些需要避免:-)!我个人认为这是最直接的:
function unique(a){
a.sort();
for(var i = 1; i < a.length; ){
if(a[i-1] == a[i]){
a.splice(i, 1);
} else {
i++;
}
}
return a;
}
// Provide your own comparison
function unique(a, compareFunc){
a.sort( compareFunc );
for(var i = 1; i < a.length; ){
if( compareFunc(a[i-1], a[i]) === 0){
a.splice(i, 1);
} else {
i++;
}
}
return a;
}
您也可以使用地图:
const dedupThings = Array.from(things.thing.reduce((m, t) => m.set(t.place, t), new Map()).values());
完整样本:
const things = new Object();
things.thing = new Array();
things.thing.push({place:"here",name:"stuff"});
things.thing.push({place:"there",name:"morestuff"});
things.thing.push({place:"there",name:"morestuff"});
const dedupThings = Array.from(things.thing.reduce((m, t) => m.set(t.place, t), new Map()).values());
console.log(JSON.stringify(dedupThings, null, 4));
结果:
[
{
"place": "here",
"name": "stuff"
},
{
"place": "there",
"name": "morestuff"
}
]