nested object replace all undefined values with null in typescript

index.ts
function replaceUndefinedWithNull(obj: {[key: string]: any }): {[key: string]: any } {
  const result: {[key: string]: any } = {};
  for (const key in obj) {
    if (obj.hasOwnProperty(key)) {
      const value = obj[key];
      if (value === undefined) {
        result[key] = null;
      } else if (typeof value === 'object') {
        result[key] = replaceUndefinedWithNull(value);
      } else {
        result[key] = value;
      }
    }
  }
  return result;
}
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index.ts
const obj = {
  prop1: undefined,
  prop2: 'value',
  prop3: {
    nestedProp1: undefined,
    nestedProp2: 'nestedValue'
  }
};

const newObj = replaceUndefinedWithNull(obj);
console.log(newObj);
// Output: { prop1: null, prop2: 'value', prop3: { nestedProp1: null, nestedProp2: 'nestedValue' } }
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