如何用TypeScript/JavaScript动态移除JSON中的指定元素？

Let's say you have a JSON structure with nested careerLevels nodes (like your example input) and you want to remove this specific key from all relevant objects. Here are practical, easy-to-implement solutions:

Approach 1: Direct Deletion (Modifies Original Object) #

If you don't mind altering the original data, you can loop through the array and delete the target key directly:

// Your sample input
const input = {
  careerLevelGroups: [
    {
      "201801": 58,
      "201802": 74,
      careerLevel: "Analyst",
      careerLevels: [
        { "201801": 29, "201802": 37, careerID: "10000100" },
        { "201801": 29, "201802": 37, careerID: "10000110" }
      ]
    },
    {
      "201801": 58,
      "201802": 74,
      careerLevel: "Consultant",
      careerLevels: [
        { "201801": 29, "201802": 37, careerID: "10000080" },
        { "201801": 29, "201802": 37, careerID: "10000090" }
      ]
    }
  ]
};

// Remove 'careerLevels' from each group
input.careerLevelGroups.forEach(group => {
  delete group.careerLevels;
});

console.log(input);
// Output will have all careerLevelGroups without the careerLevels key

Approach 2: Immutable Removal (Preserves Original Object) #

If you want to keep the original data intact, create a deep copy first, then modify the copy. This is safer for scenarios where you need the original data later:

// Deep copy using structuredClone (modern browsers/Node.js 17+)
const inputCopy = structuredClone(input);

// Remove the key from the copy
inputCopy.careerLevelGroups.forEach(group => {
  delete group.careerLevels;
});

console.log(inputCopy); // Modified version
console.log(input); // Original remains unchanged

For environments that don't support structuredClone, you can use a recursive deep copy function:

function deepCopy<T>(obj: T): T {
  if (obj === null || typeof obj !== 'object') return obj;
  if (obj instanceof Array) return obj.map(item => deepCopy(item)) as unknown as T;
  const copiedObj = {} as T;
  for (const key in obj) {
    if (obj.hasOwnProperty(key)) {
      copiedObj[key] = deepCopy(obj[key]);
    }
  }
  return copiedObj;
}

// Usage
const inputCopy = deepCopy(input);
inputCopy.careerLevelGroups.forEach(group => delete group.careerLevels);

Generic Function for Any Target Key #

To make this reusable for any key you want to remove (not just careerLevels), wrap the logic in a generic function:

function removeKeyFromArrayItems<T, K extends keyof T>(
  data: { careerLevelGroups: T[] },
  keyToRemove: K
): { careerLevelGroups: Omit<T, K>[] } {
  // Create a deep copy to avoid mutating original
  const copiedData = structuredClone(data);
  copiedData.careerLevelGroups.forEach(group => {
    delete group[keyToRemove];
  });
  return copiedData;
}

// Usage: Remove 'careerLevels'
const result = removeKeyFromArrayItems(input, 'careerLevels');

// Or remove another key like '201801'
const resultWithout201801 = removeKeyFromArrayItems(input, '201801');

This function uses TypeScript generics to enforce type safety, ensuring you only pass valid keys for the objects in the array.

内容的提问来源于stack exchange，提问作者rp4361