这是来自后端的示例JSON响应，评级是在评级数组中，值是评级，所以我想计算每个课程的平均评级，并且仍然将其作为响应返回给前端，我尝试使用Object.Assign()，但工作得很好，当我只是抓取一个课程，但当我抓取所有课程，它不起作用。
我需要帮助
{
"message": "Fetched successfully",
"status": "Success",
"statusCode": 200,
"data": {
"items": [
{
"id": 210,
"courseUuid": "93b760a7-505e-41bf-b57e-d84ecf53255f",
"userId": 2,
"title": "Complete Angularzero to hero",
"imageUrl": "https://our-akademy-uploads.s3.eu-west-1.amazonaws.com/courses/1655654436946-f02118c8-e3e9-44e5-8913-48d4f45cd816.png",
"slugUrl": "Complete-Angularzero-to-hero-19-06-2022-93b760a7-505e-41bf-b57e-d84ecf53255f",
"amount": "50,600",
"averageRating": "11.5",
"createdAt": "2022-06-19T16:00:43.009Z",
"updatedAt": "2022-06-19T23:27:46.073Z",
"user": {
"id": 2,
"userUuid": "b1f8def8-aa1d-4a57-b743-174a6ee738ec",
"email": "jessika76@hotmail.com",
"nawisNumber": "NAWIS/2022/54682884"
},
"category": {
"id": 1,
"categoryUuid": "3a4def94-dd1a-451c-8f84-476096203710",
"name": "Front-End Development",
"slugUrl": "Front-End-Development-18-06-2022-ec0a7634-b710-4723-b646-4cde33d3d15a"
},
"duration": {
"id": 23,
"durationUuid": "3500b0d0-8d98-46d6-80d8-6363c09e887c",
"duration": "5 Months"
},
"enrollments": [
{
"id": 1,
"paymentStatus": "Not Completed",
"createdAt": "2022-06-19T16:04:22.375Z",
"user": {
"id": 3,
"userUuid": "ad0b0ad4-368d-4f09-ae99-80d2bcaed3d6",
"email": "damion.jacobs84@yahoo.com",
"nawisNumber": "NAWIS/2022/12758991"
}
},
{
"id": 2,
"paymentStatus": "Not Completed",
"createdAt": "2022-06-19T16:07:37.059Z",
"user": {
"id": 6,
"userUuid": "cbfbc6a7-dfd7-4f74-a545-a1423ccdb0f3",
"email": "olaf_bailey@hotmail.com",
"nawisNumber": "NAWIS/2022/11177867"
}
}
],
"ratings": [
{
"id": 1,
"rating": 2,
"review": "some text here",
"createdAt": "2022-06-19T16:04:40.339Z",
"user": {
"id": 3,
"userUuid": "ad0b0ad4-368d-4f09-ae99-80d2bcaed3d6",
"email": "damion.jacobs84@yahoo.com"
}
},
{
"id": 2,
"rating": 5,
"review": "some text here",
"createdAt": "2022-06-19T16:07:23.798Z",
"user": {
"id": 6,
"userUuid": "cbfbc6a7-dfd7-4f74-a545-a1423ccdb0f3",
"email": "olaf_bailey@hotmail.com"
}
}
]
},
{
"id": 208,
"courseUuid": "16855bd6-dd18-420a-8611-bc77bbda818c",
"userId": 2,
"title": "Complete Vuejs zero to hero",
"imageUrl": "https://our-akademy-uploads.s3.eu-west-1.amazonaws.com/courses/1655653347091-cfee6022-0d3a-43e2-b780-986eda2607ed.png",
"slugUrl": "undefined-19-06-2022-16855bd6-dd18-420a-8611-bc77bbda818c",
"amount": "0",
"averageRating": "0",
"createdAt": "2022-06-19T15:42:30.273Z",
"updatedAt": "2022-06-19T15:53:07.726Z",
"user": {
"id": 2,
"userUuid": "b1f8def8-aa1d-4a57-b743-174a6ee738ec",
"email": "jessika76@hotmail.com",
"nawisNumber": "NAWIS/2022/54682884"
},
"category": {
"id": 1,
"categoryUuid": "3a4def94-dd1a-451c-8f84-476096203710",
"name": "Front-End Development",
"slugUrl": "Front-End-Development-18-06-2022-ec0a7634-b710-4723-b646-4cde33d3d15a"
},
"duration": {
"id": 23,
"durationUuid": "3500b0d0-8d98-46d6-80d8-6363c09e887c",
"duration": "5 Months"
},
"enrollments": [],
"ratings": []
},
{
"id": 207,
"courseUuid": "bdb3ee71-0c0b-41d8-9049-5fa6a2a230f3",
"userId": 2,
"title": "Complete Vuejs zero to hero",
"imageUrl": "https://our-akademy-uploads.s3.eu-west-1.amazonaws.com/courses/1655653325613-dda17c5c-2a4a-435a-99cb-ad28ea01bbb0.png",
"slugUrl": "Complete-Vuejs-zero-to-hero-19-06-2022-bdb3ee71-0c0b-41d8-9049-5fa6a2a230f3",
"amount": "50,600",
"averageRating": "0",
"createdAt": "2022-06-19T15:42:12.687Z",
"updatedAt": "2022-06-19T15:42:12.687Z",
"user": {
"id": 2,
"userUuid": "b1f8def8-aa1d-4a57-b743-174a6ee738ec",
"email": "jessika76@hotmail.com",
"nawisNumber": "NAWIS/2022/54682884"
},
"category": {
"id": 1,
"categoryUuid": "3a4def94-dd1a-451c-8f84-476096203710",
"name": "Front-End Development",
"slugUrl": "Front-End-Development-18-06-2022-ec0a7634-b710-4723-b646-4cde33d3d15a"
},
"duration": {
"id": 23,
"durationUuid": "3500b0d0-8d98-46d6-80d8-6363c09e887c",
"duration": "5 Months"
},
"enrollments": [],
"ratings": []
}
],
"meta": {
"totalItems": 209,
"itemCount": 3,
"itemsPerPage": 6,
"totalPages": 35,
"currentPage": 1
},
"links": {
"first": "http://ourakademy.com/api/v1/courses?limit=6",
"previous": "",
"next": "http://ourakademy.com/api/v1/courses?page=2&limit=6",
"last": "http://ourakademy.com/api/v1/courses?page=35&limit=6"
}
}
}
假设您将json响应放入sampleJson变量
let sampleJson = YOUR JSON RESPONE
let sum = 0
let noOfRatings = 0
if(sampleJson && sampleJson.data && sampleJson.data.items){
sampleJson.data.items.forEach(item => {
item.ratings.forEach(i => {
if (i && i.rating) { sum += i.rating; noOfRatings++ }
})
});
if(sum && noOfRatings){
let averateRating = sum / noOfRatings
console.log('Average Rating : ',averateRating)
}
}
您将使用此代码获得平均评级。希望能有所帮助:)
我是这样解决这个问题的
const courses: any = await this.find();
for (let i = 0; i < courses.length; i++) {
const course = courses[i];
const sum: any = course.ratings.reduce((accumulator, object) => {
return accumulator + object.rating;
}, 0);
courses[i] = {
...course,
avg: sum / course.ratings.length,
};
}
return courses;