Q19: Calculate Structural Difference Between Two Objects

Implement diffObjects(obj1, obj2) to compare two objects recursively and return a summary of added, removed, and updated properties.

Object Diffing Utility

function diffObjects(obj1, obj2) {
  const diff = {};
  const allKeys = new Set([...Object.keys(obj1), ...Object.keys(obj2)]);
  
  for (let key of allKeys) {
    if (!(key in obj1)) {
      diff[key] = { status: 'ADDED', value: obj2[key] };
    } else if (!(key in obj2)) {
      diff[key] = { status: 'REMOVED', value: obj1[key] };
    } else if (typeof obj1[key] === 'object' && typeof obj2[key] === 'object' && obj1[key] !== null && obj2[key] !== null) {
      const nestedDiff = diffObjects(obj1[key], obj2[key]);
      if (Object.keys(nestedDiff).length > 0) diff[key] = nestedDiff;
    } else if (obj1[key] !== obj2[key]) {
      diff[key] = { status: 'UPDATED', oldValue: obj1[key], newValue: obj2[key] };
    }
  }
  return diff;
}

💡 Collects keys across both objects to determine property additions, removals, and value mutations recursively.

Key Takeaways

Combines key sets to evaluate deletions, additions, and mutations.
Recursively evaluates nested object structures to identify structural changes.

Knowledge Check

How does the diffObjects algorithm identify a key that was REMOVED in obj2?

Q19: Calculate Structural Difference Between Two Objects

STAY UPDATED WITH BYTES!