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Javascript – Find objects of a certain length inside the object

I need to go through the json object and find keys-objects, keys-arrays whose size matches a given value.

I can’t understand where to set the conditions.

function traverse(obj, size) {
    for (let key in obj) {
        if (typeof obj[key] === "object" && obj[key] != null) {
            traverse(obj[key]);
            if (Object.keys(obj[key]).length > size) {
                console.log(key);
            } else if (Array.isArray(obj[key])) {
                if (obj[key].length > size) { 
                    console.log(key);
                }
            } 
        }
    }
}

I’ve tried rearranging the if conditions, but it doesn’t give any good results

Tags:

3

Answers


  1. 0

    You are calling traverse with only one argument.

    if (typeof obj[key] === "object" && obj[key] != null) {
    traverse(obj[key]); // here !
     //... rest of the code
}

    it should be

    traverse(obj[key], size);

    Please privide object example with desired result to verify the logic

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  2. 0
    1. You should pass the arguments to the recursive calls
    2. You could add an accumulator to collect the result
    3. Don’t put else if (Array.isArray(obj[key])) { where you handle an object (not an array):
    function traverse(obj, size, key = null, result = []) {
  if(Array.isArray(obj)){
    obj.forEach((item, i) => traverse(item, size, i, result));
    obj.length > size && key && result.push(key);
  } else 
  if (obj && typeof obj === "object") {
    const keys = Object.keys(obj);
    keys.forEach(key => traverse(obj[key], size, key, result));
    keys.length > size && key && result.push(key);
  }
  return result;
}

console.log(traverse({prop1: 1, prop2: [2, {prop3: 3, prop4: [1,2,3,null]}]}, 1));
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  3. 0

    I’ve corrected some parts of your function as per my understanding. This should work. If it doesn’t, let me know in the comments what error/bug you encounter. Preferably, add an instance/simplified example of the object you’re traversing to your question.

    EDIT: Here’s the final draft of a tested solution:

    /* Test Data: */
const testObject = {
  owner: 'John Doe',
  prices: [200, 450, -400, 3000, -650, -130, 70, 1300],
  interestRate: 1.2, // %
  pin: 1111,
  objOuter: {
    one: 1,
    two: 2,
    three: 3,
    arr1: [200, 450, -650],
    inner: {
      uno: 1,
      dos: 2,
      tres: 3,
      arr2: [-400, 3000],
      innermost: {
        ich: 1,
        ni: 2,
        san: 3,
        arr3: [-130, 70, 1300],
      },
    },
  },
};

/* Function: */
function traverse(obj, size) {
  for (const [key, val] of Object.entries(obj)) {
    if (Array.isArray(val) && val.length > size) {
      console.log(key);
      val.forEach(function (el, i) {
        if (typeof el === 'object') traverse(el, size);
      });
    }
    if (typeof val === 'object' && !Array.isArray(val) && Object.keys(val).length > size) {
      console.log(key);
      traverse(val, size);
    }
  }
}
traverse(testObject, 3); // Function call
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