如何在不破坏Object的情况下替换所有元素中的子串

function replaceSubstrings(obj, substring, replacement) {
  for (var key in obj) {
    if (typeof obj[key] === 'string') {
      obj[key] = obj[key].replace(new RegExp(substring, 'g'), replacement);
    } else if (typeof obj[key] === 'object') {
      replaceSubstrings(obj[key], substring, replacement); // 递归处理嵌套的Object
    }
  }
}

// 示例用法
var obj = {
  name: 'John',
  address: {
    street: '123 Main Street',
    city: 'New York',
    country: 'USA'
  },
  hobbies: ['reading', 'swimming', 'coding']
};

replaceSubstrings(obj, 'o', 'a'); // 将所有元素中的字母'o'替换为'a'

console.log(obj);