console.log(randomIdentifier);// Output: 'd5ptscfrln7';---- 检查元素是否有焦点检查是否有任何element具有只读 activeElement属性的焦点...index, newItem) => [...originalArray.slice(0, index), newItem, ...originalArray.slice(index)];const newUser...= { name: 'New User 2', id: 'newUser2',};console.log(insertNewUser(newDevToParticipants, 1, newUser...New User",// "id": "newUserId"// },// {// "name": "New User 2",// "id": "newUser2