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2823. Deep Object Filter
Description
Given an object obj
and a function fn
, return a filtered object filteredObject
.
Function deepFilter
should perform a deep filter operation on the object obj
. The deep filter operation should remove properties for which the output of the filter function fn
is false
, as well as any empty objects or arrays that remain after the keys have been removed.
If the deep filter operation results in an empty object or array, with no remaining properties, deepFilter
should return undefined
to indicate that there is no valid data left in the filteredObject
.
Example 1:
Input: obj = [-5, -4, -3, -2, -1, 0, 1], fn = (x) => x > 0 Output: [1] Explanation: All values that were not greater than 0 were removed.
Example 2:
Input: obj = {"a": 1, "b": "2", "c": 3, "d": "4", "e": 5, "f": 6, "g": {"a": 1}}, fn = (x) => typeof x === "string" Output: {"b":"2","d":"4"} Explanation: All keys with values that were not a string were removed. When the object keys were removed during the filtering process, any resulting empty objects were also removed.
Example 3:
Input: obj = [-1, [-1, -1, 5, -1, 10], -1, [-1], [-5]], fn = (x) => x > 0 Output: [[5,10]] Explanation: All values that were not greater than 0 were removed. When the values were removed during the filtering process, any resulting empty arrays were also removed.
Example 4:
Input: obj = [[[[5]]]], fn = (x) => Array.isArray(x) Output: undefined
Constraints:
fn
is a function that returns a boolean valueobj
is a valid JSON object2 <= JSON.stringify(obj).length <= 105
Solutions
-
function deepFilter(obj: Record<string, any>, fn: Function): Record<string, any> | undefined { const dfs = (data: any): any => { if (Array.isArray(data)) { const res = data.map(dfs).filter((item: any) => item !== undefined); return res.length > 0 ? res : undefined; } if (typeof data === 'object' && data !== null) { const res: Record<string, any> = {}; for (const key in data) { if (data.hasOwnProperty(key)) { const filteredValue = dfs(data[key]); if (filteredValue !== undefined) { res[key] = filteredValue; } } } return Object.keys(res).length > 0 ? res : undefined; } return fn(data) ? data : undefined; }; return dfs(obj); }