Recursive array generation

Question

Recursive array generation

Given an array 'featureList', the goal is to create a new array 'newArray' based on a specific ID. For example, for ID 5, the newArray would be ['MotherBoard','Antenna','Receiver'], where Receiver corresponds to the current ID, Antenna is from the parentID of Receiver, and MotherBoard is from the parentID of Antenna.

What recursive approach would be most effective in achieving this new array?

The current code provided below is not successfully producing the desired outcome.

const newArray: string[] = [];
    for (const feature of featureList) {
      if (feature.id === this.featureId) {
        newArray.push(feature.name);
        if (feature.parentFeatureId) {
          for (const parentFeature of featureList) {
            if (parentFeature.id === feature.parentFeatureId) {
              newArray.push(parentFeature.name);
            }
          }
        }
      }
    }


  var featureList = [
      {
        "id": 1,
        "name": "MotherBoard",
        "projectId": 1,
        "parentFeatureId": null
      },
      {
        "id": 2,
        "name": "Power Supply",
        "projectId": 1,
        "parentFeatureId": 1
      },
      {
        "id": 3,
        "name": "Antenna",
        "projectId": 1,
        "parentFeatureId": 1
      },
      {
        "id": 4,
        "name": "Transmitter",
        "projectId": 1,
        "parentFeatureId": 3
      },
      {
        "id": 5,
        "name": "Receiver",
        "projectId": 1,
        "parentFeatureId": 3
      },
      {
        "id": 6,
        "name": "Storage",
        "projectId": 1,
        "parentFeatureId": null
      },
      {
        "id": 7,
        "name": "Calibration State",
        "projectId": 1,
        "parentFeatureId": 6
      },
      {
        "id": 8,
        "name": "User Profile mgm",
        "projectId": 1,
        "parentFeatureId": 6
      },
      {
        "id": 9,
        "name": "HW State mgm",
        "projectId": 1,
        "parentFeatureId": 6
      }
    ]

javascript typescript

Answer 1

Answer №1

If you're looking to generate a list of parent names for a specified ID using recursion, here's a function you can use:

var getParents = function(id){
  var currentFeature = featureList.find(element => element.id === id);
    if (currentFeature && currentFeature.parentId)
      return [...getParents(currentFeature.parentId), currentFeature.name]
    else if (currentFeature)
      return [currentFeature.name];
    else
      return [];
};

This function takes the provided ID, searches for the corresponding object in featureList, and then creates an array containing the names of all parent features leading up to the specified object. The function uses recursion by calling itself with the parent ID.

For more information, visit https://jsfiddle.net/ps1ks89a/16/.

Answer 2

If you're looking to generate a list of parent names for a specified ID using recursion, here's a function you can use:

var getParents = function(id){
  var currentFeature = featureList.find(element => element.id === id);
    if (currentFeature && currentFeature.parentId)
      return [...getParents(currentFeature.parentId), currentFeature.name]
    else if (currentFeature)
      return [currentFeature.name];
    else
      return [];
};

This function takes the provided ID, searches for the corresponding object in featureList, and then creates an array containing the names of all parent features leading up to the specified object. The function uses recursion by calling itself with the parent ID.

For more information, visit https://jsfiddle.net/ps1ks89a/16/.

Answer 3

Answer №2

To solve this problem in vanilla JavaScript, you can implement a recursive solution that considers the current index and keeps track of visited feature names.

When the target item is found, the function returns the list of collected names.

This method relies on a sorted list where parents precede their children.

function getFeatures(id, array, parent = null, index = 0, features = []) {
    var temp;
    while (index < array.length) {
        if (array[index].parentFeatureId !== parent) {
            index++;
            continue;
        }
        if (array[index].id === id) {
            return features.concat(array[index].name);
        }
        temp = getFeatures(id, array, array[index].id, index + 1, features.concat(array[index].name));
        if (temp) {
            return temp;
        }
        index++;
    }
}

var featureList = [{ id: 1, name: "MotherBoard", projectId: 1, parentFeatureId: null }, { id: 2, name: "Power Supply", projectId: 1, parentFeatureId: 1 }, { id: 3, name: "Antenna", projectId: 1, parentFeatureId: 1 }, { id: 4, name: "Transmitter", projectId: 1, parentFeatureId: 3 }, { id: 5, name: "Receiver", projectId: 1, parentFeatureId: 3 }, { id: 6, name: "Storage", projectId: 1, parentFeatureId: null }, { id: 7, name: "Calibration State", projectId: 1, parentFeatureId: 6 }, { id: 8, name: "User Profile mgm", projectId: 1, parentFeatureId: 6 }, { id: 9, name: "HW State mgm", projectId: 1, parentFeatureId: 6 }]

console.log(getFeatures(5, featureList));

Answer 4

To solve this problem in vanilla JavaScript, you can implement a recursive solution that considers the current index and keeps track of visited feature names.

When the target item is found, the function returns the list of collected names.

This method relies on a sorted list where parents precede their children.

function getFeatures(id, array, parent = null, index = 0, features = []) {
    var temp;
    while (index < array.length) {
        if (array[index].parentFeatureId !== parent) {
            index++;
            continue;
        }
        if (array[index].id === id) {
            return features.concat(array[index].name);
        }
        temp = getFeatures(id, array, array[index].id, index + 1, features.concat(array[index].name));
        if (temp) {
            return temp;
        }
        index++;
    }
}

var featureList = [{ id: 1, name: "MotherBoard", projectId: 1, parentFeatureId: null }, { id: 2, name: "Power Supply", projectId: 1, parentFeatureId: 1 }, { id: 3, name: "Antenna", projectId: 1, parentFeatureId: 1 }, { id: 4, name: "Transmitter", projectId: 1, parentFeatureId: 3 }, { id: 5, name: "Receiver", projectId: 1, parentFeatureId: 3 }, { id: 6, name: "Storage", projectId: 1, parentFeatureId: null }, { id: 7, name: "Calibration State", projectId: 1, parentFeatureId: 6 }, { id: 8, name: "User Profile mgm", projectId: 1, parentFeatureId: 6 }, { id: 9, name: "HW State mgm", projectId: 1, parentFeatureId: 6 }]

console.log(getFeatures(5, featureList));

Recursive array generation

Answer №1

Answer №2

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