将JavaScript对象添加到for循环中的现有JavaScript对象

var obj = { name: "Alice", age: 25 };

// 向已有的对象添加新属性
obj.gender = "female";

// 向已有的对象添加新方法
obj.sayHello = function() {
  console.log("Hello!");
};

console.log(obj);

{
  name: "Alice",
  age: 25,
  gender: "female",
  sayHello: function() {
    console.log("Hello!");
  }
}

var obj = { name: "Alice", age: 25 };

for (var key in obj) {
  // 根据需求添加新属性或方法
  obj[key + "_modified"] = obj[key] + "_modified";
}

console.log(obj);

{
  name: "Alice",
  age: 25,
  name_modified: "Alice_modified",
  age_modified: "25_modified"
}