es6 过滤器 JSON 返回未定义，过滤器对象没有

Question

I have a filter function that is returning undefined only when JSON is passed into it. I'd like to use this function to filter objects, JSON or anything really. Whats the best way to make this work on both objects and JSON?

 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

You need a reference to the inner array for searching.

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"));

For a deeper find, you could use an recursive approach.

 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

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Answer 2

You can try to do a string search.

Logic

• Create a copy of object but as string using JSON.stringify
• Create a regex that searches for a pattern :<something>SearchValue .
• Test object string with this regex and return it in filter

 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