使用键数组过滤对象数组并提取其属性

Question

我有这个问题，我不能缠住我的头，

如果输入代码，会更好。

//Array of objects sample
var objects = [{id:1, name:'test1'}, {id:2, name:'test2'}, {id:3, name: 'test3'}, {id:4, name:'test4'}];
var arrayOfKeys = [3,1,4];

//extract object name property if its id property is equivalent to one of arrayOfKeys [3,1] 
//var arrayOfKeys = [3,1,4];
//output sample: extractedName=['test3','test1','test4'];

我一直在使用过滤器和地图，但无济于事，还尝试在地图内嵌套过滤器，以获取数组数组，并且内部是单个对象。

Answer 1

您可以映射对象，也可以映射想要的键以获得名称。

 var objects = [{ id: 1, name: 'test1' }, { id: 2, name: 'test2' }, { id: 3, name: 'test3' }], arrayOfKeys = [3, 1], result = arrayOfKeys.map((map => id => map.get(id).name)(new Map(objects.map(o => [o.id, o])))); console.log(result); 

Answer 2

我假设您需要将数组编号映射到id属性？ 这是代码，您find在其中map数字并在数组内部find以处理对象数组中没有此类id情况：

 var objects = [{id:1, name:'test1'}, {id:2, name:'test2'}, {id:3, name: 'test3'}]; var arrayOfKeys = [3,1]; var res = arrayOfKeys.map(key => { var found = objects.find(o => o.id == key); return found ? found.name : false; }) console.log(res) 

Answer 3

 let objects = [{id:1, name:'test1'}, {id:2, name:'test2'}, {id:3, name: 'test3'}, {id:4, name:'test4'}], arrayOfKeys = [3,1,4]; let result = objects.reduce((res, obj) => { // loop over the array of objects let index = arrayOfKeys.indexOf(obj.id); // check if the current object's id is in the array of keys if(index !== -1) { // if it's there res.push(obj.name); // then add the current object's name to the result array arrayOfKeys.splice(index, 1); // remove its id from the array of keys so we won't search for it again (optional, slightly better than leaving it there) } return res; }, []); console.log(result); 

Answer 4

我认为您在使用筛选器的过程中处于正确的轨道。 您可以使它变得可读和简洁。

 var objects = [{id: 1,name: 'test1'}, {id: 2,name: 'test2'}, {id: 3,name: 'test3'}, {id: 4,name: 'test4'}], arrayOfKeys = [3, 1, 4]; var result = objects.filter((x, i) => { if (arrayOfKeys.some(k => x.id === k)) { return true; } }) console.log(result.map(x=>x.name)); 

更短的东西！ 将会

 var objects = [{id: 1,name: 'test1'}, {id: 2,name: 'test2'}, {id: 3,name: 'test3'}, {id: 4,name: 'test4'}],arrayOfKeys = [3, 1, 4]; var result = objects.filter((x, i) => arrayOfKeys.some(k => x.id === k)); console.log(result.map(x=>x.name));