如果对象包含某些东西，js删除所有数组元素

Question

我有一个对象数组Course。

export interface Course {
    id: string;
    student: User[];
    color: string;
}

export interface User {
    id: string;
    name: string;
    //...
}

如果他里面的学生数组包含特定的id，我需要删除Course数组的所有元素

我试图做类似的事情，但我不明白我应该在过滤器部分做什么。

const deleteCourseWhereImIn = (courses: Course[]) => {
    const myid = "1111"
    return courses.filter((item):Course => 
        //[...]
    )
};

示例：

输入：

const courses = [
    {
        id : "JSLKLDK",
        student: [
            {
                id: "1111",
                name: "John"
            },
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "3333",
                name: "Tim"
            },
       ],
       color: "#f01000",
    },
    {
        id : "5JLDKLD",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "1111",
                name: "John"
            },
       ],
       color: "#511131",
    },
    {
        id : "PDLFMLZ",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
       ],
       color: "#ffffff",
    },
]

我的 ID 是1111

输出应该是：

const courses = [
    {
        id : "PDLFMLZ",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
       ],
       color: "#ffffff",
    },
]

因为我是 john，我不在这门课程中。

Answer 1

请试试这个。
我在函数 deleteCourseWhereImIn() 中传递课程数组，然后说 myId 是“1111”。我正在检查学生数组中是否有任何学生具有此 ID，从而使用 some() 方法返回布尔值。然后根据真假过滤该特定课程。

    const deleteCourseWhereImIn = (courses: Course[]) => {
      const myId = "1111";
      let filteredCourses = courses.filter(course => {
        let studentArr = course.student;
        let filterdStudent = studentArr.some(student => student.id === myId);
        return !filterdStudent;
        
      });
    
      console.log('Filtered Course', filteredCourses);
    }
    
    deleteCourseWhereImIn(courses);  // calling function 

Answer 2

您可以使用filter 和some 过滤条件为id: "1111" 的课程。 在您的描述中，您提到要删除您所在的课程。

为此，您可以在函数 deleteCourseWhereImIn 中使用此过滤器，并将其返回的内容分配给您的 Course[]。

let courses = [
    {
        id : "JSLKLDK",
        student: [
            {
                id: "1111",
                name: "John"
            },
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "3333",
                name: "Tim"
            },
       ],
       color: "#f01000",
    },
    {
        id : "5JLDKLD",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "1111",
                name: "John"
            },
       ],
       color: "#511131",
    },
    {
        id : "PDLFMLZ",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
       ],
       color: "#ffffff",
    },
]

courses = courses.filter(course => {
    return !course.student.some(student => student.id === "1111");
});


console.log(courses);

Answer 3

使用filter 和findIndex：

const deleteCourseWhereImIn = (courses: Course[]) => {
    const myid = "1111";
    return courses.filter(item =>
        return item.student.findIndex(user => user.id == myid) === -1
    );
};

这里有一个详细的版本来更好地说明正在发生的事情：

const deleteCourseWhereImIn = (courses: Course[]) => {
    const myid = "1111";

    const filteredCourses = courses.filter(item: Course => {
        const index = item.student.findIndex(user: User => {
             return user.id == myid
        });

        // The method findIndex() will return -1 if the value you search for does not appear in the array.
        return index === -1;
    });

    return filteredCourses;
};

Answer 4

只使用javascript的功能特性。

const courses = [... your courses ...]
const idToCheck = "1111"
let newCourses = courses.filter(x => 
    x.student.findIndex(y => y.id == idToCheck) === -1)

Answer 5

最好使用reduce生成一个新数组并赋值给Course

let courses = [
    {
        id : "JSLKLDK",
        student: [
            {
                id: "1111",
                name: "John"
            },
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "3333",
                name: "Tim"
            },
       ],
       color: "#f01000",
    },
    {
        id : "5JLDKLD",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "1111",
                name: "John"
            },
       ],
       color: "#511131",
    },
    {
        id : "PDLFMLZ",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
       ],
       color: "#ffffff",
    },
]
courses = courses.reduce((arr, c)=>{
  if(!c.student.some((s)=>(s.id==='1111'))){
    arr.push(c);
  }
  return arr
},[])
console.log(courses);

Answer 6

使用filter 和every：

const myID = "1111";

const courses = [
    {
        id : "JSLKLDK",
        student: [
            {
                id: "1111",
                name: "John"
            },
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "3333",
                name: "Tim"
            },
       ],
       color: "#f01000",
    },
    {
        id : "5JLDKLD",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
            {
                id: "1111",
                name: "John"
            },
       ],
       color: "#511131",
    },
    {
        id : "PDLFMLZ",
        student: [
            {
                id: "2222",
                name: "Ronald"
            },
       ],
       color: "#ffffff",
    },
]

const filtered = courses.filter(c => c.student.every(s => s.id !== myID))

console.log(filtered);