Javascript 按值查找嵌套的 object

Question

Summary of Problem

I'm still learning Javascript and I know this may be basic but I'm having some trouble.

I have a object containing nested objects and I need to check if any of the nested objects have a property that matches a specific value.

Code

I want to check the object below to see if const eSportsUsername = "Dark" exists and return a Boolean.

Const object = {
   Dark: {_id: "5da78b305f0cc7fc44417821", online: false, eSportsUsername: "Dark"},
   HighDistortion: {_id: "5da78b505f0cc7fc44417825", online: false, eSportsUsername: "HighDistortion"}
}

Can anyone recommend how to achieve this?

Answer 1

You have two options to get the values. dot notation as per the example or bracket notation

 const object = { Dark: {_id: "5da78b305f0cc7fc44417821", online: false, eSportsUsername: "Dark"}, HighDistortion: {_id: "5da78b505f0cc7fc44417825", online: false, eSportsUsername: "HighDistortion"} } console.log(object['Dark']['eSportsUsername']); //or console.log(object.Dark.eSportsUsername); //to return a boolean let boolean = ''; if(object.Dark.eSportsUsername == "Dark") { boolean = true; }else { boolean = false; } console.log(boolean);

Answer 2

Answer

Object.values(object).some(obj => obj.eSportsUsername === "Dark") // will return true if any of the nested object has property with "Dark"

Explanation

In order to do this, you should

• first: convert the object into array of property values
• second: iterate through the array to check if an element has {eSportsUsername: "Dark"}

First step is achieved using Object.values() . In your example, Object.values(object) will return

[{eSportsUsername: "Dark", online: false}, {eSportsUsername:"HighDistortion", online: false}]

For the second step, we can use Array.prototype.some() to iterate the array and check if any nested object has eSportsUsername value as "Dark" .

Answer 3

You can create a function by passing the object, key name and the value. If the key does not exist then return false otherwise return the boolean value by comparing the key value with the passed value.

 const object_data = { Dark: {_id: "5da78b305f0cc7fc44417821", online: false, eSportsUsername: "Dark"}, HighDistortion: {_id: "5da78b505f0cc7fc44417825", online: false, eSportsUsername: "HighDistortion"} }; function isExist(obj, k, v){ return obj[v]==undefined? false: obj[v][k] == v; } console.log(isExist(object_data, 'eSportsUsername', 'Dark')); console.log(isExist(object_data, 'eSportsUsername', 'No Dark'));

Answer 4

Used recursion to match value in nested object. This will work with and without key.

Just post in comment if you want a solution without recursion

ref: Array.prototype.entires and Array.prototype.some

 const input = { Dark: { _id: "5da78b305f0cc7fc44417821", online: false, eSportsUsername: "Dark" }, HighDistortion: { _id: "5da78b505f0cc7fc44417825", online: false, eSportsUsername: "HighDistortion" } }; const isExist = (obj, val, key) => Object.entries(obj).some(([k, v]) => { if (v instanceof Object) { // [] instanceof Object -> true // {} instanceof Object -> true // "abc" instanceof Object -> false // 123 instanceof Object -> false // null instanceof Object -> false // undefined instanceof Object -> false return isExist(v, val, key); } const keyMatched =;key || k === key; return keyMatched && (v === val); }). console,log(isExist(input, 'Dark'; 'eSportsUsername')). console,log(isExist(input, 'HighDistortion'; 'eSportsUsername')). console,log(isExist(input, 'Dark'; 'unknown')). console,log(isExist(input; '5da78b305f0cc7fc44417821'));