我有这样的数组结构：
[Array[2].attributes, Array[6].attributes] contains list of objects
第一个数组包含post_id的博文，第二个数组包含comment，comment_id和{的博客评论{1}}
我想计算每个帖子的评论数量，并为post_id
完整结构：
post_id我一直在尝试这样但却无法正常工作：
[
[
{
"attributes":{
"created_at":"3/30/2017, 1:33:37 AM",
"details":"aaa",
"id":116,
"post_id":"1490817817738",
"title":" Technologies - Learn to code Java, Spring, Angular etc",
"url":"-technologies---learn-to-code-java,-spring,-angular-etc",
"userImage":"assets/img/spiritual-icon4.png",
"username":".k999@gmail.com"
}
},
{
"attributes":{
"created_at":"3/30/2017, 12:11:28 PM",
"details":"aaa",
"id":117,
"post_id":"1490856088450",
"title":"Express JS Tutorial",
"url":"express-js-tutorial",
"userImage":"assets/img/spiritual-icon4.png",
"username":".k999@gmail.com"
}
}
],
[
{
"attributes":{
"comment_id":"1490817936990",
"content":"hi",
"created_at":"2017-03-29 20:05:36",
"id":28,
"likes":"",
"post_id":"1490817817738",
"userImage":"https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50",
"username":".k999@gmail.com"
}
},
{
"attributes":{
"comment_id":"1490856043965",
"content":"hi",
"created_at":"2017-03-30 06:40:43",
"id":29,
"likes":"",
"post_id":"1490817817738",
"userImage":"https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50",
"username":".k999@gmail.com"
}
},
{
"attributes":{
"comment_id":"1490856048963",
"content":"hwllo",
"created_at":"2017-03-30 06:40:48",
"id":30,
"likes":"",
"post_id":"1490817817738",
"userImage":"https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50",
"username":".k999@gmail.com"
}
},
{
"attributes":{
"comment_id":"1490856056938",
"content":"hello",
"created_at":"2017-03-30 06:40:56",
"id":31,
"likes":"",
"post_id":"1490817817738",
"userImage":"https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50",
"username":".k999@gmail.com"
}
},
{
"attributes":{
"comment_id":"1490856093828",
"content":"aaa",
"created_at":"2017-03-30 06:41:33",
"id":32,
"likes":"",
"post_id":"1490856088450",
"userImage":"https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50",
"username":".k999@gmail.com"
},
},
{
"attributes":{
"comment_id":"1490856096261",
"content":"sss",
"created_at":"2017-03-30 06:41:36",
"id":33,
"likes":"",
"post_id":"1490856088450",
"userImage":"https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50",
"username":".k999@gmail.com"
},
}
]
]
更新
var commentCount = Object.create(null);
self.postId = Object.create(null);
res[1].forEach(function(el , i) {
console.log('el ', el);
commentCount[el.attributes.post_id] = (commentCount[el.attributes.comment_id] || 0) +1;
});
console.log('self.commentCount ', commentCount);
答案 0 :(得分：1)
基本上，您不使用post_id的相同参考。
commentCount[el.attributes.post_id] = (commentCount[el.attributes.comment_id] || 0) + 1
// ^^^^^^^ ^^^^^^^^^^
但你需要
commentCount[el.attributes.post_id] = (commentCount[el.attributes.post_id] || 0) + 1
// ^^^^^^^ ^^^^^^^
您可以迭代第二个数组并计算给定post_id
var data = [[{ attributes: { created_at: "3/30/2017, 1:33:37 AM", details: "aaa", id: 116, post_id: 1490817817738, title: " Technologies - Learn to code Java, Spring, Angular etc", url: "-technologies---learn-to-code-java,-spring,-angular-etc", userImage: "assets/img/spiritual-icon4.png", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, details: { columnName: "details", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, title: { columnName: "title", typeName: "TEXT", columnSize: 65535 }, url: { columnName: "url", typeName: "VARCHAR", columnSize: 1000 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 45 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 45 } }, associations: [{ fkName: "post_id", source: "com..seeker.models.Post", target: "com..seeker.models.PostsCategories" }, { fkName: "post_id", source: "com..seeker.models.Post", target: "com..seeker.models.Comment" }], idName: "id", tableName: "post", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Post", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }, { attributes: { created_at: "3/30/2017, 12:11:28 PM", details: "aaa", id: 117, post_id: 1490856088450, title: "Express JS Tutorial", url: "express-js-tutorial", userImage: "assets/img/spiritual-icon4.png", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, details: { columnName: "details", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, title: { columnName: "title", typeName: "TEXT", columnSize: 65535 }, url: { columnName: "url", typeName: "VARCHAR", columnSize: 1000 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 45 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 45 } }, associations: [{ fkName: "post_id", source: "com..seeker.models.Post", target: "com..seeker.models.PostsCategories" }, { fkName: "post_id", source: "com..seeker.models.Post", target: "com..seeker.models.Comment" }], idName: "id", tableName: "post", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Post", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }], [{ attributes: { comment_id: 1490817936990, content: "hi", created_at: "2017-03-29 20:05:36", id: 28, likes: 0, post_id: 1490817817738, userImage: "https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { comment_id: { columnName: "comment_id", typeName: "TEXT", columnSize: 65535 }, content: { columnName: "content", typeName: "TEXT", columnSize: 65535 }, created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, likes: { columnName: "likes", typeName: "TEXT", columnSize: 65535 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, updated_at: { columnName: "updated_at", typeName: "TEXT", columnSize: 65535 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 200 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 200 } }, associations: [{ fkName: "comment_id", source: "com..seeker.models.Comment", target: "com..seeker.models.CommentRating" }, { fkName: "post_id", source: "com..seeker.models.Comment", target: "com..seeker.models.Post" }], idName: "id", tableName: "comment", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Comment", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }, { attributes: { comment_id: 1490856043965, content: "hi", created_at: "2017-03-30 06:40:43", id: 29, likes: 0, post_id: 1490817817738, userImage: "https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { comment_id: { columnName: "comment_id", typeName: "TEXT", columnSize: 65535 }, content: { columnName: "content", typeName: "TEXT", columnSize: 65535 }, created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, likes: { columnName: "likes", typeName: "TEXT", columnSize: 65535 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, updated_at: { columnName: "updated_at", typeName: "TEXT", columnSize: 65535 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 200 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 200 } }, associations: [{ fkName: "comment_id", source: "com..seeker.models.Comment", target: "com..seeker.models.CommentRating" }, { fkName: "post_id", source: "com..seeker.models.Comment", target: "com..seeker.models.Post" }], idName: "id", tableName: "comment", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Comment", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }, { attributes: { comment_id: 1490856048963, content: "hwllo", created_at: "2017-03-30 06:40:48", id: 30, likes: 0, post_id: 1490817817738, userImage: "https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { comment_id: { columnName: "comment_id", typeName: "TEXT", columnSize: 65535 }, content: { columnName: "content", typeName: "TEXT", columnSize: 65535 }, created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, likes: { columnName: "likes", typeName: "TEXT", columnSize: 65535 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, updated_at: { columnName: "updated_at", typeName: "TEXT", columnSize: 65535 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 200 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 200 } }, associations: [{ fkName: "comment_id", source: "com..seeker.models.Comment", target: "com..seeker.models.CommentRating" }, { fkName: "post_id", source: "com..seeker.models.Comment", target: "com..seeker.models.Post" }], idName: "id", tableName: "comment", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Comment", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }, { attributes: { comment_id: 1490856056938, content: "hello", created_at: "2017-03-30 06:40:56", id: 31, likes: 0, post_id: 1490817817738, userImage: "https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { comment_id: { columnName: "comment_id", typeName: "TEXT", columnSize: 65535 }, content: { columnName: "content", typeName: "TEXT", columnSize: 65535 }, created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, likes: { columnName: "likes", typeName: "TEXT", columnSize: 65535 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, updated_at: { columnName: "updated_at", typeName: "TEXT", columnSize: 65535 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 200 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 200 } }, associations: [{ fkName: "comment_id", source: "com..seeker.models.Comment", target: "com..seeker.models.CommentRating" }, { fkName: "post_id", source: "com..seeker.models.Comment", target: "com..seeker.models.Post" }], idName: "id", tableName: "comment", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Comment", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }, { attributes: { comment_id: 1490856093828, content: "aaa", created_at: "2017-03-30 06:41:33", id: 32, likes: 0, post_id: 1490856088450, userImage: "https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { comment_id: { columnName: "comment_id", typeName: "TEXT", columnSize: 65535 }, content: { columnName: "content", typeName: "TEXT", columnSize: 65535 }, created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, likes: { columnName: "likes", typeName: "TEXT", columnSize: 65535 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, updated_at: { columnName: "updated_at", typeName: "TEXT", columnSize: 65535 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 200 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 200 } }, associations: [{ fkName: "comment_id", source: "com..seeker.models.Comment", target: "com..seeker.models.CommentRating" }, { fkName: "post_id", source: "com..seeker.models.Comment", target: "com..seeker.models.Post" }], idName: "id", tableName: "comment", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Comment", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }, { attributes: { comment_id: 1490856096261, content: "sss", created_at: "2017-03-30 06:41:36", id: 33, likes: 0, post_id: 1490856088450, userImage: "https://lh3.googleusercontent.com/-/AAAAAAAAAAI/AAAAAAAAAAA/4252rscbv5M/photo.jpg?sz=50", username: ".k999@gmail.com" }, dirtyAttributeNames: [], frozen: false, metaModelLocal: { columnMetadata: { comment_id: { columnName: "comment_id", typeName: "TEXT", columnSize: 65535 }, content: { columnName: "content", typeName: "TEXT", columnSize: 65535 }, created_at: { columnName: "created_at", typeName: "TEXT", columnSize: 65535 }, id: { columnName: "id", typeName: "MEDIUMINT", columnSize: 7 }, likes: { columnName: "likes", typeName: "TEXT", columnSize: 65535 }, post_id: { columnName: "post_id", typeName: "TEXT", columnSize: 65535 }, updated_at: { columnName: "updated_at", typeName: "TEXT", columnSize: 65535 }, userImage: { columnName: "userImage", typeName: "VARCHAR", columnSize: 200 }, username: { columnName: "username", typeName: "VARCHAR", columnSize: 200 } }, associations: [{ fkName: "comment_id", source: "com..seeker.models.Comment", target: "com..seeker.models.CommentRating" }, { fkName: "post_id", source: "com..seeker.models.Comment", target: "com..seeker.models.Post" }], idName: "id", tableName: "comment", dbType: "MySQL", dbName: "default", modelClass: "com..seeker.models.Comment", cached: false, versionColumn: "record_version" }, modelRegistryLocal: { callbacks: [], attributeConverters: {}, validators: [] }, cachedParents: {}, cachedChildren: {}, manageTime: true, compositeKeyPersisted: false, errors: {} }]],
count = Object.create(null);
data[1].forEach(function (a) {
count[a.attributes.post_id] = (count[a.attributes.post_id] || 0) + 1;
});
console.log(count);.as-console-wrapper { max-height: 100% !important; top: 0; }