javascript forEach on数组/ json数据，但按最新日期排序？

Question

Is it possible to modify the following so that on the foreach it would reverse so that latest date of data is first rather than oldest to newest?

 var json = { "TrackingRecord": { "Authorised": "Authorised(5.77.48.131)", "DeliveryAddress": { "CompanyName": "JAMES DERICK", "Address1": "6", "Address2": "LIBER HOUSE", "Address3": "OLYMPIAN", "Town": "YORK", "Postcode": "YO10 3UF", "ContactName": "JAMES DERICK", "ContactTelephone": "7507346318" }, "CollectionAddress": { "CompanyName": "AMBIENT LOUNGE LTD", "Address1": "UNIT 3 LONG HEDGE LANE INDUSTR", "Address2": "BOTTESFORD", "Address3": { }, "Town": "NOTTINGHAM", "Postcode": "NG13 0BF", "ContactName": "SARAH KIRBY", "ContactTelephone": "07879 442266074" }, "ConsignmentInformation": { "Pieces": "1", "Pallets": "0", "Weight": "10", "Service": "Priority 1", "DeliveryDate": "2016-02-29T00:00:00", "ItemsDelivered": "1", "ConsignmentRef": "2838", "SpecialInstructions": "JAMES DERICK 7507346318 {JAMES\
    
    
    
      14075@GMAIL.COM}\ 
     
       ", "AdditionalReferencesInformation": { "AdditionalReferences": { "Reference": "2838" } } }, "MovementInformation": { "Movement": [{ "MovementDate": "2016-02-25T00:00:00", "MovementTime": "0001-01-01T10:00:04", "Description": "Created By EZEEWEB", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-26T00:00:00", "PackagesReceived": "0", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-26T00:00:00", "MovementTime": "0001-01-01T07:11:53", "Description": "Out to deliver", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-26T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-26T00:00:00", "MovementTime": "0001-01-01T11:00:53", "Description": "Failed - Other reason", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-29T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-27T00:00:00", "MovementTime": "0001-01-01T05:59:32", "Description": "Out to deliver", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-29T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-29T00:00:00", "MovementTime": "0001-01-01T10:55:43", "Description": "Delivered", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-29T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "1" }] }, "TimedInformation": { "TimedDelivery": { "Signature": "DERICK", "SignatureDate": "2016-02-29T00:00:00", "SignatureTime": "0001-01-01T10:55:00" } }, "ScanInformation": { "Scan": [{ "PieceID": "148426702251072001", "Description": "Auto Inbound Scan ()", "Depot": "Newark", "ScanDate": "2016-02-25T00:00:00", "ScanTime": "0001-01-01T17:12:01", "ScannedBy": "NWK CONVYR" }, { "PieceID": "148426702251072001", "Description": "Auto Inbound Scan ()", "Depot": "Leeds", "ScanDate": "2016-02-26T00:00:00", "ScanTime": "0001-01-01T02:22:08", "ScannedBy": "LDS CONVYR" }, { "PieceID": "148426702251072001", "Description": "Load C & D (019)", "Depot": "Leeds", "ScanDate": "2016-02-26T00:00:00", "ScanTime": "0001-01-01T03:37:45", "ScannedBy": "CJONES" }, { "PieceID": "148426702251072001", "Description": "Load C & D (019)", "Depot": "Leeds", "ScanDate": "2016-02-26T00:00:00", "ScanTime": "0001-01-01T23:43:22", "ScannedBy": "CJONES" }] }, "ImageInformation": { "PODImage": { "URL": "http:\\/\\/www.tpeweb.co.uk\\/ezpod\\/tpenas\\/valid\\/20160229\\/014842672838___________00000_01.tif" } } } } json.TrackingRecord.MovementInformation.Movement.forEach(function(item) { //console.log(item); item.MovementDate = moment(item.MovementDate).format('ddd, Do of MMM YYYY'); item.MovementTime = moment(item.MovementTime).format('hh:mm a'); $("#movement tbody").append("<tr><td>" + item.MovementDate + "</td><td>" + item.MovementTime + "</td><td>" + item.Description + "</td></tr>"); }) 
      
     

 <script src="https://cdn.jsdelivr.net/momentjs/2.11.2/moment.min.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> <table id="movement"> <thead> <tr> <th>Date</th> <th>Time</th> <th>Status</th> </tr> </thead> <tbody> </tbody> </table> 

Answer 1

Not with plain forEach . Possibilities:

• Assume it is in ascending order. Loop indices from length - 1 to 0 . Nondestructive.
• Assume it is in ascending order. Apply reverse , then forEach . Destructive.
• Assume it is unsorted. Sort the array, then apply forEach . Destructive.
• Assume it is unsorted. Create an array of indices, sort the indices by the corresponding values in the array, apply forEach on indices and access array members. Nondestructive.
• Assume it is unsorted. Clone the array using slice , then apply sort and forEach . Nondestructive.

Answer 2

You could change

json.TrackingRecord.MovementInformation.Movement.forEach(function(item) {

to

json.TrackingRecord.MovementInformation.Movement.reverse().forEach(function(item) {
                                                 ^^^^^^^^^

 var json = { "TrackingRecord": { "Authorised": "Authorised(5.77.48.131)", "DeliveryAddress": { "CompanyName": "JAMES DERICK", "Address1": "6", "Address2": "LIBER HOUSE", "Address3": "OLYMPIAN", "Town": "YORK", "Postcode": "YO10 3UF", "ContactName": "JAMES DERICK", "ContactTelephone": "7507346318" }, "CollectionAddress": { "CompanyName": "AMBIENT LOUNGE LTD", "Address1": "UNIT 3 LONG HEDGE LANE INDUSTR", "Address2": "BOTTESFORD", "Address3": { }, "Town": "NOTTINGHAM", "Postcode": "NG13 0BF", "ContactName": "SARAH KIRBY", "ContactTelephone": "07879 442266074" }, "ConsignmentInformation": { "Pieces": "1", "Pallets": "0", "Weight": "10", "Service": "Priority 1", "DeliveryDate": "2016-02-29T00:00:00", "ItemsDelivered": "1", "ConsignmentRef": "2838", "SpecialInstructions": "JAMES DERICK 7507346318 {JAMES\
    
    
    
      14075@GMAIL.COM}\ 
     
       ", "AdditionalReferencesInformation": { "AdditionalReferences": { "Reference": "2838" } } }, "MovementInformation": { "Movement": [{ "MovementDate": "2016-02-25T00:00:00", "MovementTime": "0001-01-01T10:00:04", "Description": "Created By EZEEWEB", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-26T00:00:00", "PackagesReceived": "0", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-26T00:00:00", "MovementTime": "0001-01-01T07:11:53", "Description": "Out to deliver", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-26T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-26T00:00:00", "MovementTime": "0001-01-01T11:00:53", "Description": "Failed - Other reason", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-29T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-27T00:00:00", "MovementTime": "0001-01-01T05:59:32", "Description": "Out to deliver", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-29T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "0" }, { "MovementDate": "2016-02-29T00:00:00", "MovementTime": "0001-01-01T10:55:43", "Description": "Delivered", "DeliveryDepot": "Leeds", "Round": "019", "DeliveryDate": "2016-02-29T00:00:00", "PackagesReceived": "1", "PackagesDelivered": "1" }] }, "TimedInformation": { "TimedDelivery": { "Signature": "DERICK", "SignatureDate": "2016-02-29T00:00:00", "SignatureTime": "0001-01-01T10:55:00" } }, "ScanInformation": { "Scan": [{ "PieceID": "148426702251072001", "Description": "Auto Inbound Scan ()", "Depot": "Newark", "ScanDate": "2016-02-25T00:00:00", "ScanTime": "0001-01-01T17:12:01", "ScannedBy": "NWK CONVYR" }, { "PieceID": "148426702251072001", "Description": "Auto Inbound Scan ()", "Depot": "Leeds", "ScanDate": "2016-02-26T00:00:00", "ScanTime": "0001-01-01T02:22:08", "ScannedBy": "LDS CONVYR" }, { "PieceID": "148426702251072001", "Description": "Load C & D (019)", "Depot": "Leeds", "ScanDate": "2016-02-26T00:00:00", "ScanTime": "0001-01-01T03:37:45", "ScannedBy": "CJONES" }, { "PieceID": "148426702251072001", "Description": "Load C & D (019)", "Depot": "Leeds", "ScanDate": "2016-02-26T00:00:00", "ScanTime": "0001-01-01T23:43:22", "ScannedBy": "CJONES" }] }, "ImageInformation": { "PODImage": { "URL": "http:\\/\\/www.tpeweb.co.uk\\/ezpod\\/tpenas\\/valid\\/20160229\\/014842672838___________00000_01.tif" } } } } json.TrackingRecord.MovementInformation.Movement.reverse().forEach(function(item) { //console.log(item); item.MovementDate = moment(item.MovementDate).format('ddd, Do of MMM YYYY'); item.MovementTime = moment(item.MovementTime).format('hh:mm a'); $("#movement tbody").append("<tr><td>" + item.MovementDate + "</td><td>" + item.MovementTime + "</td><td>" + item.Description + "</td></tr>"); }) 
      
     

 <script src="https://cdn.jsdelivr.net/momentjs/2.11.2/moment.min.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> <table id="movement"> <thead> <tr> <th>Date</th> <th>Time</th> <th>Status</th> </tr> </thead> <tbody> </tbody> </table> 

Keep in mind that reverse actually modifies the array, it doesn't just return an array with the elements reversed. However, this is probably what you want considering it's supposed to be printed in that order.

Answer 3

A non–destructive way to iterate backwards over an array (other than a plain for loop) is reduceRight :

json.TrackingRecord.MovementInformation.Movement.reduceRight(function(acc, item) {
  // do stuff
}, null);