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更新时间：2022-12-10 10:03:20
一个简单的 ES6 解决方案是使用 filter 获取匹配 id 的元素，然后获取过滤后数组的长度:
const array = [{id: 12, name: 'toto'},{id: 12, name: 'toto'},{id: 42, name: 'tutu'},{id: 12, name: 'toto'},];常量 ID = 12;const count = array.filter((obj) => obj.id === id).length;console.log(count);编辑:另一种更有效的解决方案(因为它不生成新数组)是使用 reduce 作为 @YosvelQuintero 建议:
const array = [{id: 12, name: 'toto'},{id: 12, name: 'toto'},{id: 42, name: 'tutu'},{id: 12, name: 'toto'},];常量 ID = 12;const count = array.reduce((acc, cur) => cur.id === id ? ++acc : acc, 0);console.log(count);I would like to know how i can count the number of occurences on an array of object like this one :
[
{id : 12,
name : toto,
},
{id : 12,
name : toto,
},
{id : 42,
name : tutu,
},
{id : 12,
name : toto,
},
]
in this case i would like to have a function who give me this :
getNbOccur(id){
//don't know...//
return occurs;
}
and if i give the id 12 i would like to have 3.
How can i do that?
A simple ES6 solution is using filter to get the elements with matching id and, then, get the length of the filtered array:
const array = [
{id: 12, name: 'toto'},
{id: 12, name: 'toto'},
{id: 42, name: 'tutu'},
{id: 12, name: 'toto'},
];
const id = 12;
const count = array.filter((obj) => obj.id === id).length;
console.log(count);
Edit: Another solution, that is more efficient (since it does not generate a new array), is the usage of reduce as suggested by @YosvelQuintero:
const array = [
{id: 12, name: 'toto'},
{id: 12, name: 'toto'},
{id: 42, name: 'tutu'},
{id: 12, name: 'toto'},
];
const id = 12;
const count = array.reduce((acc, cur) => cur.id === id ? ++acc : acc, 0);
console.log(count);