如何在javascript对象中找到最接近的下限和大写的值？

function findClosestValue(obj, target) {
  let closestLower = -Infinity; // 最接近下限的初始值设为负无穷大
  let closestUpper = Infinity; // 最接近上限的初始值设为正无穷大

  for (let key in obj) {
    if (obj.hasOwnProperty(key)) {
      let value = obj[key];
      if (value <= target && value > closestLower) {
        closestLower = value;
      }
      if (value >= target && value < closestUpper) {
        closestUpper = value;
      }
    }
  }

  return {
    closestLower: closestLower,
    closestUpper: closestUpper
  };
}

// 示例对象
let obj = {
  key1: 10,
  key2: 20,
  key3: 30,
  key4: 40
};

// 要查找的目标值
let target = 25;

// 调用函数并输出结果
let result = findClosestValue(obj, target);
console.log("最接近下限的值：" + result.closestLower);
console.log("最接近上限的值：" + result.closestUpper);

最接近下限的值：20
最接近上限的值：30