There is a dataset:
array_A[1~10], arrayB[1~40], array_C[1-30]
I need to classify those dataset,
the result like below.
classify_array_1: some from array_A, some from array_B, some from array_C
classify_array_2: some from array_A, some from array_B, some from array_C
classify_array_3: some from array_A, some from array_B, some from array_C
classify_array_4: the rest.
So In javascript
One way
I can make use of array to store object with those(with type = A, type = B, type = C, and index in the original array), and push the related item to certain array.
classify_array_1 = [];
classify_array_2 = [];
classify_array_3 = [];
classify_array_4 = [];
however, when I need to visit a value: array_A 7, I need to visit all of those classify_array_[1-4] array to find this item(type=A&& id=7)
Another way
I can just create 3 array to store the original data
array_A[1~10], arrayB[1~40], array_C[1-30]
and then put certain to (but add a item in array_A[4].classify=3 )
classify_array_1 = [];
classify_array_2 = [];
classify_array_3 = [];
classify_array_4 = [];
As I know when I make change in classify_array_[1-4], there will also change in array_[ABC],
and when I need to find A 4, I just get from the array_A, and to look its classify property we know the classify information.
But in this way we need another 3 arrays, Is there a good way?
What the data is very huge?
Any suggestion is appreciated, thanks.
Related
I am iterating thorugh an array and trying to get different data for each object in array but I end up with same data, if i have three products in billBodies i end up with three item that have the same value (for example i have 3 candies, 2 coffees, and 4 candy bars result I get is 4 candy, 4 candy, 4 candy).
Hope anyone can help i tried to search similar problems but didn't find it though...
for (let bill of dataOfBillHeader.billBodies) {
console.log(dataOfBillHeader)
console.log(this.productToShowOnView)
this.productToShowOnView.cipher = bill.product.cipher;
this.productToShowOnView.name = bill.product.name;
this.productToShowOnView.measure = bill.product.measure;
this.productToShowOnView.count = bill.product.count;
this.productToShowOnView.price = bill.product.price;
this.productToShowOnView.id = dataOfBillHeader.id;
this.productToShowOnView.count = bill.count;
this.productToShowOnView.quantity = bill.quantity;
this.productToShowOnView.discount = bill.discount;
this.productToShowOnView.discountAmount = bill.discountAmount;
this.productToShowOnView.totalPrice = bill.totalPrice;
console.log("to show on view is " + JSON.stringify(this.productToShowOnView));
const newBasket = this.productsInBasket;
this.productsInBasket.push(this.productToShowOnView);
this.productsInBasket = [...newBasket];
this.cd.detectChanges();
}
Well, you are just pushing the same object (reference) in there over and over, namely this.productToShowOnView. Why are you using this.productToShowOnView? Why not a local constant. And with a little magic you can make it a bit smaller, although I don't understand why you would go from one product data format to another one...:
const newBasket = [...this.productsInBasket];
for (let bill of dataOfBillHeader.billBodies) {
const product = {
// no need to get all those individually
...bill.product,
...bill,
//this is weird, all products have the same id?
id: dataOfBillHeader.id,
};
newBasket.push(product);
}
this.productsInBasket = newBasket;
this.cd.detectChanges();
I am trying to loop through a dictionary of customers and save energy usage data, but for some customers when I try to change the values in their usage dictionary it will also change a completely different customer's value. I have a nested dictionary with customer utility information, the top-level key being a unique internal ID.
I stripped my code down to a single loop, looping through the top-level keys and setting the same month's usage for all customers in the dictionary to be the value of the iterator. After that, as shown in the code sample below, I log the values for three customers. After that, I increment only one of those customer's usage, and log the values again. The console shows that two over the customer's have dictionaries that are tied together somehow, but I can't figure out why or how to solve this. I can't discern any pattern in the keys of the linked customers, either.
Structure of the nested dictionary:
CustDict =
{"N0100000XXXXXX" =
{"name" = "XXXX"},
{"address" = "XXXX"},
{"meter_read_dates" =
{"2021-05-13" =
{"usage" = "XXXX"}
}
}
}
Stripped down code I used to demonstrate what is happening as simply as possible (real ID values):
Logger.log(custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000000419887"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000012580668"]["meter_read_dates"]["2021-05-13"]["usage"])
custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"] =
custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"] + 1
Logger.log(custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000000419887"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000012580668"]["meter_read_dates"]["2021-05-13"]["usage"])
Console Output:
11:54:56 AM Info 346.0
11:54:56 AM Info 346.0
11:54:56 AM Info 322.0
11:54:56 AM Info 347.0
11:54:56 AM Info 347.0
11:54:56 AM Info 322.0
Code used to create the CustDict dictionary:
stmtCR = conn.prepareStatement('SELECT cust_id, utility_account, cycle_id, read_cycle FROM customers')
results = stmtCR.executeQuery()
resultsMetaData = results.getMetaData()
numCols = resultsMetaData.getColumnCount();
results.last();
numRows = results.getRow();
i = 0
results.first()
var custDict = {}
while (i < numRows)
{
custDict[results.getString(1)] = {}
custDict[results.getString(1)]["id"] = results.getString(1)
custDict[results.getString(1)]["utility_account"] = results.getString(2)
custDict[results.getString(1)]["cycle_id"] = results.getString(3)
custDict[results.getString(1)]["read_cycle"] = results.getString(4)
results.next()
i++;
}
for (i = 0; i < Object.keys(custDict).length; i++)
{
tempCust = custDict[Object.keys(custDict)[i]]
tempCycleId = tempCust["cycle_id"]
tempReadCycle = tempCust["read_cycle"]
tempCust["meter_read_dates"] = cycleIdShdDict[tempCycleId][tempReadCycle]
custDict[Object.keys(custDict)[i]] = tempCust
}
cycleIdShdDict is a seperate dictionary that contains a set of dates associated with each cycle_id and read_cycle
I suspect the problem is that Object.keys(custDict) is returning the keys in a different order at different places in the for loop. So you're getting the object from one key, and then assigning it to a different key.
There's no need to assign back to custDict[Object.keys(custDict)[i]] since you're modifying the object in place, not a copy.
But instead of looping through the keys, loop through the values and modify them.
Object.values(custDict).forEach(tempCust => {
let tempCycleId = tempCust["cycle_id"];
let tempReadCycle = tempCust["read_cycle"];
tempCust["meter_read_dates"] = cycleIdShdDict[tempCycleId][tempReadCycle];
});
I have 2 Arrays and one is 2 dimensional and another is 1 dimensional. I need to compare both and need to store there common data in another array. I tried the below approach:-
tw.local.listtodisplayNW = new tw.object.listOf.listtodisplayNWBO();
//if(tw.local.SQLResults[0].rows.listLength >
// tw.local.virtualServers.listLength)
var k=0;
for (var i=0;i<tw.local.SQLResults[0].rows.listLength;i++)
{
log.info("Inside SQLResults loop - For RuntimeID: "
+tw.local.SQLResults[0].rows[i].data[3]);
for(var j=0;j<tw.local.virtualServers.listLength;j++)
{
log.info("Inside API loop - For RuntimeID: "
+tw.local.virtualServers[j].runtimeid);
if(tw.local.SQLResults[0].rows[i].data[3] ==
tw.local.virtualServers[j].runtimeid)
{
tw.local.listtodisplayNW[k] = new tw.object.listtodisplayNWBO();
tw.local.listtodisplayNW[k].vsysName =
tw.local.virtualServers[j].virtualSystemName;
tw.local.listtodisplayNW[k].vsysID =
tw.local.virtualServers[j].virtualSystemId;
tw.local.listtodisplayNW[k].serverName =
tw.local.virtualServers[j].serverName;
tw.local.listtodisplayNW[k].serverID =
tw.local.virtualServers[j].serverId;
tw.local.listtodisplayNW[k].runtimeID =
tw.local.virtualServers[j].runtimeid;
//tw.local.listtodisplayNW[k].IPAddress =
tw.local.virtualServers[j].nics[j].ipAddress;
log.info("VsysName:
"+tw.local.listtodisplayNW[k].vsysName+"RuntimeID:
"+tw.local.listtodisplayNW[k].runtimeID);
//tw.local.listtodisplayNW[k] = new
tw.object.listtodisplayNWBO();
tw.local.listtodisplayNW[k].currentSpeed =
tw.local.SQLResults[0].rows[i].data[5];
log.info("VsysName:
"+tw.local.listtodisplayNW[k].vsysName+"RuntimeID:
"+tw.local.listtodisplayNW[k].runtimeID+"CurrentSpeed:
"+tw.local.listtodisplayNW[k].currentSpeed);
if(tw.local.listtodisplayNW[k].currentSpeed != "100 Mbps")
{
tw.local.listtodisplayNW[k].desiredSpeed = "100 Mbps";
}
else
{
tw.local.listtodisplayNW[k].desiredSpeed = "1 Gbps";
}
log.info("DesiredSpeed:
"+tw.local.listtodisplayNW[k].desiredSpeed);
k++;
}
}
log.info("Length of
listtodisplayNW"+tw.local.listtodisplayNW.listLength);
}
In above code SQLResults is a 2-d array and virtualServers is a 1-D array.
I need to compare both these array and common data need to be store in another array. Here performance is not good. Is there any other way to do this efficiently. Please make a needful favour and Thanks in advance.
Assuming integer data, the following example works on the theme of array implementation of set intersection, which will take care of performance.
Convert 2D array to 1D.
var 2DtoIDArray = 2DArray.join().split(",");
Create an array named marker whose purpose is to serve as a lookup that element.
This needs to be done as follows.
Iterate through the smaller array, say 1DArray and keep setting marker as follows throughout iteration.
marker[1DArray[counter]]='S1';
Now iterate through 2Dto1DArray array(you may use nested loop iteration if you dont want to convert it to 1 dimesnional) and for each element
of this array check if its marked as 'S1' in the marker lookup array.
If yes, keep adding the elements in the commonElementsArray.
Follow this simple approach
Since the matching condition is only one between the two large arrays, create two maps (one for each array) to map each record against that attribute which is to be matched
For SQLResults
var map1 = {};
tw.local.SQLResults[0].rows.each( function(row){
map1[ row.data[3] ] = row;
});
and similarly for virtual servers
var map2 = {};
tw.local.virtualServers.each( function(vs){
map2[ vs.runtimeid ] = vs;
});
Now iterate these two maps wrt to their keys and set the values in new array
new array being tw.local.listtodisplayNW
tw.local.listtodisplayNW = [];
Object.keys( map1 ).forEach( function( key ){
if( map2[ key ] )
{
//set the values in tw.local.listtodisplayNW
}
})
Complexity of the approach is simply O(n) since there is no nested loops.
This is my code
$scope.studentDetails=[];
$scope.studentIds={};
$scope.studentIds[0]{"id":"101"}
$scope.studentIds[1]{"id":"102"}
$scope.studentIds[2]{"id":"103"}
in the above code when i select student id:101 i got marks from services like
$scope.studentMarks={};
$scope.studentMarks[0]{"marks":"67"}
$scope.studentMarks[1]{"marks":"34"}
next i select student id:102 i got marks from services like
$scope.studentMarks={};
$scope.studentMarks[0]{"marks":"98"}
$scope.studentMarks[1]{"marks":"85"}
finally i want to store student details in to one array like
$scope.studentDetails=[{"id":"101","marks":[67,34]},{"id":"102","marks":[98,85]}]
using angularjs.
Seems like its more of a JS question than angular.
What about the Javascript push method?
$scope.studentDetails.push({id: 101, marks: [67, 34]});
You can use Array.push to add one object, or concat, to concat array into another array. See the references.
angularJS is just a library to extend Javascript. You push into an array just like you would any object in Javascript.
First off, you need to declare an array.
$scope.studentIds = []; // Array of student ids.
Then when you want to add, you push:
$scope.studentIds.push({id: "101"});
To do this naively you need to loop through the student ids and then loop through the marks object and adding it to your studentDetails object if the ids match:
var studentDetails = [];
for (var id in studentIds) {
var studentDetail = {}; // this will be a single student
var marks = [];
if (studentIds.hasOwnProperty(id)) {
for (var mark in studentMarks) {
if (studentMarks.hasOwnProperty(mark) && mark.id === id) {
studentDetail.id = id;
marks.push(mark.marks);
}
}
studentDetail.marks = marks;
}
studentDetails.push(studentDetail);
}
$scope.studentDetails = studentDetails;
How may I retrieve an element that exists in two different arrays of the same document.
For example. In Posts collection, document has the fields 'interestbycreator' and 'interestbyreader.' Each field contain user Ids.
'interestbycreator': //an array of ids here. IdA, idB, IdC, IdD, IdE,
'interestbyreader': //an array of ids here. IdB, idE, iDF
Basically I wish to find all the ids that exist in both arrays, so that should be IdB and IdE.
I am able to pluck all the values from an array with underscore and store them in a variable. Can they be compared to each other this way and return duplicates? Or can someone shed some light on another solution.
Example to retrieve all Ids from 'interestbyreader
var interestbypostcreater = Posts.find({_id: Meteor.user().profile.postcreated[0]}, {fields: {interestbyreader: 1}}).fetch();
var interestedReaderIds = _.chain(interestbypostcreator).pluck('interestbyreader').flatten().value();
Assume I have the other array 'interestbycreator' stored in a variable called interestIdcreator, can they be compared to find duplicates and return these duplicates?
As saimeunt said in the comments when you have access to underscore use intersection but you can also do it with plain javascript:
var x = ['IdA', 'idB', 'IdC', 'IdD', 'IdE'];
var y = ['idB', 'IdE', 'IdF'];
var z = x.filter(function(val) {
return y.indexOf(val) != -1;
});
console.log(z);
The array z contains the double entries then.
Credits to https://stackoverflow.com/a/14930567/441907
As Saimeunt pointed out, it can be done as
var x = ['IdA', 'idB', 'IdC', 'IdD', 'IdE'];
var y = ['idB', 'IdE', 'IdF'];
var z = _.intersection(x, y);