As said in the title, I need to add the values of my keys.
Here is what I'm doing :
var repeat=ListeInterv[interv].week_data[numsemaine][intensit];
for (var i=0;i<repeat;i++)
{tabpush.push(intensit);}
console.log(tabpush);
For instance (Cardio is intensit):
{ Cardio : 3,
}
I would have in my array :
[Cardio,Cardio,Cardio]
Then I'll use array.lengh, but I don't think this the best option...
I do this because I don't know how to count down the positive values :
{ sport1: 2,
sport2 : -1,
sport3 : 1,
}
Answer I would like (in both cases) is :
3
The Array method will be very long (I have a huge amount of data), my method is in an "if" for positive values.
Any tips ?
Related
I am trying to get a kind of "leaderboard" from a list of numbers. I was thinking of making an array with all the numbers like this
var array = [];
for (a = 0; a < Object.keys(wallets.data).length; a++) { //var wallets = a JSON (parsed) response code from an API.
if (wallets.data[a].balance.amount > 0) {
array.push(wallets.data[a].balance.amount)
}
}
//Add some magic code here that sorts the array into descending numbers
This is a great option, however I need some other values to come with the numbers (one string). That's why I figured JSON would be a better option than an array.
I just have no idea how I would implement this.
I would like to get a json like this:
[
[
"ETH":
{
"balance":315
}
],
[
"BTC":
{
"balance":654
}
],
[
"LTC":
{
"balance":20
}
]
]
And then afterwards being able to call them sorted descending by balance something like this:
var jsonarray[0].balance = Highest number (654)
var jsonarray[1].balance = Second highest number (315)
var jsonarray[2].balance = Third highest number (20)
If any of you could help me out or point me in the right direction I would appreciate it greatly.
PS: I need this to happen in RAW JS without any html or libraries.
You should sort the objects before making them a JSON. You can write your own function or use a lambda. See this [https://stackoverflow.com/questions/1129216/sort-array-of-objects-by-string-property-value]
Since you are dealing with cryptocurrency you can use the currency-code as a unique identifier.
Instead of an array, you can define an object with the currency as properties like this:
const coins = {
ETH: [300, 200, 500],
BTC: [20000, 15000, 17000]
}
then you can access each one and use Math.max or Math.min to grab the highest / lowest value of that hashmap. E.G. Math.max(coins.BTC)
And if you need to iterate over the coins you have Object.keys:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
Thank you all for your answer. I ended up using something like:
leaderboard = []
for (a = 0; a < Object.keys(wallets.data).length; a++) {
if (wallets.data[a].balance.amount > 0) {
leaderboard.push({"currency":wallets.data[a].balance.currency, "price":accprice}) //accprice = variable which contains the value of the userhold coins of the current coin in EUR
}
}
console.log(leaderboard.sort(sort_by('price', true, parseInt)));
Presentation :
I am working on a piece of code that can compare two javascript Object by looping into the first one (called A) to perform a key lookup in the second one called B (I put value as key and occurence as value).
But when I am measuring the performance of the subkey key lookup of Object A (10 times per amount of data, with data as changing parameters for each 10 times the program runs (100 per row, 200...) I get high timing for the smallest amount of data (so potentially less key in the dict B)
Objects layout :
Object A looks like below:
{
SQL_TABLE_1:
{
column_1:
[
'2jmj7l5rSfeb/vlWAYkK/YBwIDk=',
'3MaRDFGBKvsLLhrLUdplz3wUiOI=',
'PEvUFHDR4HbOYXcj7danOvyRJqs='
'XHvERAKZ4AqU+iWlx2scZXdem80=',
'nSG0lvwlkIe5YxZGTo5binr3pAw=',
'Swuc/7YCU9Ptfrff+KHaJJ1+b7U=',
'N28qqdfezfZbPmK7CaGmj7m7IOQ=',
'ffc7skeffegT1ZytAqjco3EpwUE=',
'2XldayBefzBxsUuu6tMFYHVZEEY=',
'5rC2y6IzadQ1aEy7CvNyr30JJ2k='
]
},
SQL_TABLE_2:
{
column_1:[......]
}
}
Object B field have various size but this size never change in our tests
And Object B looks like:
[
field_1:
{
'2jmj7l5rSfeb/vlWAYkK/YBwIDk=': 1,
'3MaRDFGBKvsLLhrLUdplz3wUiOI=': 1,
'PEvUFHDR4HbOYXcj7danOvyRJqs=': 1,
'XHvERAKZ4AqU+iWlx2scZXdem80=': 4,
'nSG0lvwlkIe5YxZGTo5binr3pAw=': 1,
'Swuc/7YCU9Ptfrff+KHaJJ1+b7U=': 1,
'N28qqdfezfZbPmK7CaGmj7m7IOQ=': 27,
'ffc7skeffegT1ZytAqjco3EpwUE=': 1,
'2XldayBefzBxsUuu6tMFYHVZEEY=': 18,
'5rC2y6IzadQ1aEy7CvNyr30JJ2k=': 1 },
field_2:{......}
]
Timing measurement in the code is structured like this:
sql_field_1:
{
mongo_field_1: 0.003269665241241455, mongo_field_2: 0.0015446391105651855, mongo_field_3: 0.0009834918975830079, mongo_field_4: 0.0004488091468811035,
},
sql_field_2:
{
....
}
Goal
The goal is to perform for each sub-subkey of Object A a key lookup on the Object B subkeys.
Code
Here's the code that cause this behavior:
Object A is called sql_dict_array
Object B is called hash_mongo_dict
for(var field_name in hash_mongo_dict)
{
performance_by_mongo_field[field_name] = {};
result_by_mongo_field[field_name] = {};
// LOOP ON OBJECT A KEYS
for(var table_name in sql_dict_array)
{
// Start of time measurement
var start_time = performance.now();
// there is only one column in our test data
for(var column_name in sql_dict_array[table_name])
{
found_count = 0;
for(var value of sql_dict_array[table_name][column_name])
{
// **SUBKEY LOOPKUP HERE WITH VALUE**
var results = hash_mongo_dict[field_name][value];
// IF NOT UNDEFINED THEN IT HAS BEEN FOUND
// THIS CHECK IS NOT THE BOTTLENECK
if(results != undefined)
{
found_count+=results;
}
}
if(found_count > limit_parameter)
{
console.log("error: too many match between hashes")
process.exit(0)
}
// PERFORMANCE CALCULATION
performance_by_mongo_field[field_name][table_name] = (performance.now() - start_time)/1000;
result_by_mongo_field[field_name][table_name+'.'+column_name] = (found_count/verif_hash_count*100);
}
}
return some results...
}
Testing:
With this code, I expect to have almost constant time whatever the size of the Object B (amount of subkey) but in my code I have higher time when I have only 10 subkeys in the nested object A, and it become stable when reaching 100 keys or more (tested with 6000 keys)
Here's 10 runs for the key lookup code of one key of Object A containing 10 subkeys with 300.000+ data from Object B:
0.2824700818061829 0.2532380700111389 0.2455208191871643 0.2610406551361084 0.2840422649383545 0.2344329071044922 0.2375670108795166 0.23545906591415405 0.23111085414886476 0.2363566837310791
Here's the same comparison but with 4000+ subkeys:
0.0027927708625793456 0.0018292622566223144 0.015235211849212647 0.0036304402351379395 0.002919149875640869 0.004972007751464844 0.014655702114105225 0.003572652339935303 0.0032280778884887697 0.003232938766479492
I will appreciate every advice you can provide me,
I have an XmlListModel in QML
XmlListModel {
id: model
source: "qrc:/Config/myConfig.xml"
query: "/levels/level"
XmlRole { name: "levName"; query: "#levName/string()" }
XmlRole { name: "from"; query: "from/number()" }
XmlRole { name: "to"; query: "to/number()" }
}
that reads this XML file
<levels parId = "3">
<level levelName = "level1">
<from>0</from>
<to>1</to
</level>
<level levelName = "level2">
<from>1</from>
<to>2</to>
</level>
</levels>
I also have a text element:
Text {
id: myText
x: 0; y:0
text: ""
}
I need to iterate through the XmlListModel in order to assign to myText.text the right level on the basis of what I found in myList.get(3).value, where myList is a ListModel.
Example:
if myList.get(3).value is between 0 (included) and 1 (excluded) I have to set myText.text = "level1", if it is between 1 (included) and 2 (excluded) I have to set myText.text = "level2", and so on...
Any suggestion?
Unfortunately you can't query your XmlListModel in O(1) like give me the value, where x is between role from and role to.
Good for you, you have an ordered list, so you can perform a binary search on your XmlListModel. The algorithm basically goes like this:
You first check whether your search value is by coincidence the one in the middle. If it is smaller, you search in the middle of the lower half, if it is larger, you search in the upper half... and so on.
With this you can find your value in O(log n) where n is the number of entries in your XmlListModel.
https://en.wikipedia.org/wiki/Binary_search_algorithm
If you have this implemented, to work on your model - either in JavaScript or in C++ or Python... you can have it like this:
Text {
text: binarySearch(model, myList.get(3).value).levName
}
When you implement this algorithm, make sure to deal with the gaps.
Given these documents:
db.orders.insert( {OrderId:1, OrderItems: [{OrderItemId:1, Qty:1}, {OrderItemId:2, Qty:1} ]} );
db.orders.insert( {OrderId:2, OrderItems: [{OrderItemId:1, Qty:1}, {OrderItemId:2, Qty:2} ]} );
I'd like to get the count of all OrderItems where the Qty = 1 (expected result 3). This is how I think to write the query, but it returns 2 (1 for each Order document):
db.orders.find({"OrderItems.Qty":1}).count();
How can I query to find the count of all OrderItems where the Qty = 1?
Just to be clear for others reading this thread.
The OP's command db.orders.find({"OrderItems.Qty":1}).count(); basically counts the number of Documents where any order item has a quantity of 1.
However, the OP wants a count of all OrderItems where the quantity is one. The problem here is that we're not counting Documents. We're counting items within an array within a Document. Hence the need for javascript and some form of special reduce operation.
You could use JavaScript:
db.orders.group(
{
key: null,
cond: {'OrderItems.Qty':1},
initial: {count: 0},
reduce: function(el, running)
{
running.count += el.OrderItems.filter(function(el)
{
return el.Qty == 1;
}).length;
}
});
This should do it for you in the shell without JavaScript (so it'll be a lot quicker);
db.orders.aggregate([
{$unwind:'$OrderItems'},
{$match: {'OrderItems.Qty':1}},
{$group : {
_id : "Qty1",
sum: {$sum:1}
}}
]);
Although it's unfortunate your data is structured like that if this is a common query. Having to do an $unwind is relatively expensive. It's a shame your order items aren't laid out as separate documents tagged with the order ID instead of orderID documents containing arrays of order items...in other words, the reverse of what you have. That would be much easier and more efficient to process.
db.orders.aggregate([
{$unwind: '#OrderItems'},
{$match : {'OrderItems.Qty':1}},
{$group : { _id : null, 'countOfQty1':{$sum:'$OrderItems.Qty'} }}
]);
I'm working on a scoring script for contract bridge, just for giggles. I'm storing the game as an object:
var game = {
team1 : { player1 : prompt("Team 1, first player: "), player2 : prompt("Team 1, second player:") },
team2 : { player1 : prompt("Team 2, first player: "), player2 : prompt("Team 2, second player:") },
}
function deal(bid){
console.log("The bid was " + bid);
game.hand = {"bid" : bid , "made" : undefined};
score();
}
So what I'd like to do though, better than this, is to keep a history of the games played this session. I'd like to, in pseudocode, do something like this:
game.(hand + (hand.length+1))
or something kind of like that; basically auto-increment a certain object within an object. I'm not so sure an array would would here, but perhaps? I'm open to suggestions/bettering of my code.
PS - I'd prefer to do this in javascript, not jQuery, Prototype, Dojo, MooTools... or any other library. Thanks!
EDIT
Sorry, let me clarify: The result after playing 3 hands or so would be an object like this:
var game = {
team1 : { player1 : prompt("Team 1, first player: "), player2 : prompt("Team 1, second player:") },
team2 : { player1 : prompt("Team 2, first player: "), player2 : prompt("Team 2, second player:") },
hand1 : { bid : 2 , made : 2 } ,
hand2 : { bid : 1 , made : 4 } ,
hand3 : { bid : 3 , made : 1 } ,
hand4 : { bid : 2 , //and made hasn't been set yet because we're mid-hand
}
Given your pseudocode, you can do the following:
game[hand + (hand.length+1)]
i.e. game["prop"] == game.prop - both provide access to the same property.
Old question, I see but I have a need to do something similar. I'd vote up the answer but I'm not allowed.
It appears the fastest way to do this is to access the object like a hash / associative array.
var d = {};
var z = "hand";
d[z+1] = "foo";
console.log(d.hand1);
Test this out in firebug. Seems to work pretty well.
JS does not seem to have an php equivalent to force resolution of the variables as in the curley braces around an expression.
d->{z+1} = "foo"; // can't find anything like this in JS.
Hope that helps,