es6过滤器JSON返回undefined，过滤器对象没有

Question

我有一个过滤函数，只有在传入JSON时才返回undefined。我想使用这个函数来过滤对象，JSON或其他任何东西。什么是在对象和JSON上使这个工作的最佳方法？

let a = [{
  "employees": {
    "employee": [{
      "id": "1",
      "firstName": "Tom",
      "lastName": "Cruise"
    }, {
      "id": "2",
      "firstName": "Maria",
      "lastName": "Sharapova"
    }, {
      "id": "3",
      "firstName": "James",
      "lastName": "Bond"
    }]
  }
}];

var b = [{
  name: '',
  grade: 'x'
}, {
  name: 'yaya',
  grade: 'x'
}, {
  name: 'x',
  frade: 'd'
}, {
  name: 'a',
  grade: 'b'
}];

function findIt(arr, searchKey) {
  return arr.filter(obj => Object.keys(obj).some(key => obj[key].includes(searchKey)));
}

if (a) {
  console.log("I found: ", findIt(a, "James")); // breaks
}

if (b) {
  console.log("I found: ", findIt(b, "yaya")); // works fine
}

Answer 1

您需要引用内部数组进行搜索。

findIt(a[0].employees.employee, "James"));
//      ^^^^^^^^^^^^^^^^^^^^^^

let a = [{ employees: { employee: [{ id: "1", firstName: "Tom", lastName: "Cruise" }, { id: "2", firstName: "Maria", lastName: "Sharapova" }, { id: "3", firstName: "James", lastName: "Bond" }] } }];
var b = [{ name: '', grade: 'x' }, { name: 'yaya', grade: 'x' }, { name: 'x', frade: 'd' }, { name: 'a', grade: 'b' }];

function findIt(arr, searchKey) {
    return arr.filter(obj => Object.keys(obj).some(key => obj[key].includes(searchKey)));
}

console.log(findIt(a[0].employees.employee, "James"));
console.log(findIt(b, "yaya"));

为了更深入的发现，您可以使用递归方法。

function findIt(object, search) {
    function find(k) {
        if (object[k] === search) {
            return result = object;
        }
        return result = findIt(object[k], search);
    }

    var result;
    if (object && typeof object === 'object') {
        Object.keys(object).some(find);
    }
    return result;
}


var a = [{ employees: { employee: [{ id: "1", firstName: "Tom", lastName: "Cruise" }, { id: "2", firstName: "Maria", lastName: "Sharapova" }, { id: "3", firstName: "James", lastName: "Bond" }] } }],
    b = [{ name: '', grade: 'x' }, { name: 'yaya', grade: 'x' }, { name: 'x', frade: 'd' }, { name: 'a', grade: 'b' }];

console.log(findIt(a, "James"));
console.log(findIt(b, "yaya"));
console.log(findIt(a, "foo"));   // undefined

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

您可以尝试进行字符串搜索。

逻辑

• 使用JSON.stringify
创建对象的副本，但作为字符串
• 创建一个搜索模式:<something>SearchValue。
的正则表达式
• 使用此正则表达式测试对象字符串并将其返回到过滤器

let a = [{ employees: { employee: [{ id: "1", firstName: "Tom", lastName: "Cruise" }, { id: "2", firstName: "Maria", lastName: "Sharapova" }, { id: "3", firstName: "James", lastName: "Bond" }] } }];
var b = [{ name: '', grade: 'x' }, { name: 'yaya', grade: 'x' }, { name: 'x', frade: 'd' }, { name: 'a', grade: 'b' }];


function findIt(arr, searchKey) {
  let reg = new RegExp(':(.*?)' + searchKey, 'g');
  return arr.filter(obj => reg.test(JSON.stringify(obj)));
}

console.log("I found: ", findIt(a, "James")); // breaks

console.log("I found: ", findIt(a[0].employees.employee, "James")); // breaks

console.log("I found: ", findIt(b, "yaya")); // works fine