有一个对象数组，需要添加新的对象。如何检查是否只存在一个键:值对

function checkSingleKeyValuePair(objects) {
  let result = true;
  
  objects.forEach((object, index) => {
    const keys = Object.keys(object);
    if (keys.length !== 1) {
      result = false;
      // 可在此处存储索引或其他信息
      console.log(`Object at index ${index} has ${keys.length} key-value pairs.`);
    }
  });
  
  return result;
}

// 示例对象数组
const objects = [
  { key1: 'value1' },
  { key2: 'value2', key3: 'value3' },
  { key4: 'value4' },
];

// 检查对象数组
const isSingleKeyValuePair = checkSingleKeyValuePair(objects);
console.log(`Is single key-value pair? ${isSingleKeyValuePair}`);