Dealing with looping through nested arrays-CodePudding

I have data array, which has nested arrays inside (level1arr, leve21arr ...)

const data = [
  {
    level1arr: [
      {
        level2arr: [{ id: 1, isValid: true }, { id: 2, isValid: true }, { id: 3, isValid: true }],
      },
      {
        level2arr: [{ id: 4, isValid: true }, { id: 5, isValid: true }, { id: 6, isValid: true }],
      },
    ],
  },
  {
    level1arr: [
      {
        level2arr: [{ id: 7, isValid: true }, { id: 8, isValid: true }, { id: 9, isValid: true }],
      },
      {
        level2arr: [{ id: 10, isValid: true }, { id: 11, isValid: true }, { id: 12, isValid: true }],
      },
    ],
  },
];

I also have another array:

const invalidIds = [2,5]

I want to find elements with apecyfic id and change isValid property to false. Is it better way than iteratinf over multiple nested arrays, like that:

data.forEach(lvl1 => {
  lvl1.level1arr.forEach(lvl2 => {
    lvl2.level2arr.forEach(element => {
      // further nesting
    });
  });
})

Such iterating over multiple arrays is not good for performance. What is the best way to handle such case with nested arrays?

CodePudding user response：

If it were nested arrays, you could use Array.prototype.flat(). However, you have a mix of nested objects and arrays. You will have to write a custom "flattener" for this data structure. Check this answer for details: how to convert this nested object into a flat object?

CodePudding user response：

You can use recursion until you reach the level you need. Here's one way to do it.

const data = [{
    level1arr: [{
        level2arr: [{
          id: 1,
          isValid: true
        }, {
          id: 2,
          isValid: true
        }, {
          id: 3,
          isValid: true
        }],
      },
      {
        level2arr: [{
          id: 4,
          isValid: true
        }, {
          id: 5,
          isValid: true
        }, {
          id: 6,
          isValid: true
        }],
      },
    ],
  },
  {
    level1arr: [{
        level2arr: [{
          id: 7,
          isValid: true
        }, {
          id: 8,
          isValid: true
        }, {
          id: 9,
          isValid: true
        }],
      },
      {
        level2arr: [{
          id: 10,
          isValid: true
        }, {
          id: 11,
          isValid: true
        }, {
          id: 12,
          isValid: true
        }],
      },
    ],
  },
];

const invalidIds =[2,5]

const findId = (object, key, value) => {
  if (Array.isArray(object)) {
    for (const obj of object) {
      findId(obj, key, value);
    }
  } else {
    if (object.hasOwnProperty(key) && object[key] === value) {
      object.isValid = false;
      return object
    }
    for (const k of Object.keys(object)) {
      if (typeof object[k] === "object") {
        findId(object[k], key, value);
      }
    }
  }
}

invalidIds.forEach(id => findId(data, "id", id))
console.log(data)