Javascript - 如何在包含 arrays 的对象中遍历对象？

Question

Let's say I have an object that contains objects as well as arrays --

const models = {
    characters: {
        human: {
            male: {
                short: [
                    { url: 'resources/models/characters/human/male/short/male0.fbx' },
                ],
                tall: [
                    { url: 'resources/models/characters/human/male/tall/male0.fbx' },
                ]
            },
            female: [
                { url: 'resources/models/characters/human/female/female0.fbx' },
                { url: 'resources/models/characters/human/female/female0.fbx' },
            ],
        },
        orc: {
            male: [
                
            ],
            female: [
                
            ],
        }
    },
    objects: {
        floors: {
            wood: [
                { url: 'resources/models/objects/floors/wood/floor_wood_000.obj' },
                { url: 'resources/models/objects/floors/wood/floor_wood_001.obj' },
                { url: 'resources/models/objects/floors/wood/floor_wood_002.obj' },
                { url: 'resources/models/objects/floors/wood/floor_wood_003.obj' }
            ],
        },
        walls: {
            wood: [
                
            ],
        },
        stairs: {
            wood: [
                
            ],
        },
        bed: [
            { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' },
            { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' }
        ],
    }
};

var count = {
    characters: numberOfUrlsInCharacters,
    objects: numberofUrlsInObjects
};

Now I want to count how many URLs in total the object models contains. Would I have to count this manually, or is there an easier way?

Also, notice the objects are not equal. They all contain different amount of objects & arrays.

Answer 1

Since you mentioned that the structure of the data is not consistent, it would make your task very easy if you stringify the object, and then look for the keyword "url": to get a count of the URLs present.

const strigifiedModels = JSON.stringify(models);

const count = (strigifiedModels.match(/"url":/g) || []).length;

Working snippet:

 const models = { characters: { human: { male: { short: [{ url: 'resources/models/characters/human/male/short/male0.fbx' }, ], tall: [{ url: 'resources/models/characters/human/male/tall/male0.fbx' }, ], female: [{ url: 'resources/models/characters/human/female/female0.fbx' }, { url: 'resources/models/characters/human/female/female0.fbx' }, ], }, orc: { male: [], female: [], }, }, objects: { floors: { wood: [{ url: 'resources/models/objects/floors/wood/floor_wood_000.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_001.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_002.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_003.obj' }, ], }, walls: { wood: [], }, stairs: { wood: [], }, bed: [{ url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' }, { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' }, ], }, }, }; const strigifiedModels = JSON.stringify(models); const count = (strigifiedModels.match(/"url":/g) || []).length; console.log(count);

Answer 2

Recursive Nonsense:

 const models = { characters: { human: { male: { short: [ { url: 'resources/models/characters/human/male/short/male0.fbx' }, ], tall: [ { url: 'resources/models/characters/human/male/tall/male0.fbx' }, ] }, female: [ { url: 'resources/models/characters/human/female/female0.fbx' }, { url: 'resources/models/characters/human/female/female0.fbx' }, ], }, orc: { male: [ ], female: [ ], } }, objects: { floors: { wood: [ { url: 'resources/models/objects/floors/wood/floor_wood_000.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_001.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_002.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_003.obj' } ], }, walls: { wood: [ ], }, stairs: { wood: [ ], }, bed: [ { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' }, { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' } ], } }; const countUrls = (thing) => { let count = 0; if (Array.isArray(thing)) { count += thing.reduce((acc, el) => acc + countUrls(el), 0); } else if (typeof thing === "object") { if (thing.url) { count++; } else { count += Object.values(thing).reduce((acc, el) => acc + countUrls(el), 0); } } return count; }; console.log(countUrls(models)); console.log(countUrls(models.characters.human));

Answer 3

Try this :

 const models = { characters: { human: { male: { short: [ { url: 'resources/models/characters/human/male/short/male0.fbx' }, ], tall: [ { url: 'resources/models/characters/human/male/tall/male0.fbx' }, ] }, female: [ { url: 'resources/models/characters/human/female/female0.fbx' }, { url: 'resources/models/characters/human/female/female0.fbx' }, ], }, orc: { male: [ ], female: [ ], } }, objects: { floors: { wood: [ { url: 'resources/models/objects/floors/wood/floor_wood_000.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_001.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_002.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_003.obj' } ], }, walls: { wood: [ ], }, stairs: { wood: [ ], }, bed: [ { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' }, { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' } ], } }; const numberOfUrlsInCharacters = JSON.stringify(models.characters).match(/"url":/ig).length; const numberofUrlsInObjects = JSON.stringify(models.objects).match(/"url":/ig).length; var count = { characters: numberOfUrlsInCharacters, objects: numberofUrlsInObjects }; console.log(count);

Answer 4

Recursive look up. Just assumes that url will aways be in array of objects.

 const models = { characters: { human: { male: { short: [{ url: 'resources/models/characters/human/male/short/male0.fbx' }, ], tall: [{ url: 'resources/models/characters/human/male/tall/male0.fbx' }, ] }, female: [{ url: 'resources/models/characters/human/female/female0.fbx' }, { url: 'resources/models/characters/human/female/female0.fbx' }, ], }, orc: { male: [ ], female: [ ], } }, objects: { floors: { wood: [{ url: 'resources/models/objects/floors/wood/floor_wood_000.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_001.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_002.obj' }, { url: 'resources/models/objects/floors/wood/floor_wood_003.obj' } ], }, walls: { wood: [ ], }, stairs: { wood: [ ], }, bed: [{ url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' }, { url: 'resources/models/objects/bed/objects_bed_mattress_000.obj' } ], } }; const countUrls = (item) => { if (Array.isArray(item)) { return item.reduce((c, x) => x.url? c + 1: c, 0); } else { return Object.values(item).reduce((cnt, x) => cnt + countUrls(x), 0); } } const result = Object.entries(models).reduce((acc, [key, obj]) => { acc[key] = countUrls(obj); return acc; }, {}); console.log(result);