Develop Reference

How to find the most duplicate "values" in javascript array?

my question is actually similar to: Extracting the most duplicate value from an array in JavaScript (with jQuery)
I Found this but it always return one value only which is 200.
var arr = [100,100,200,200,200,300,300,300,400,400,400];
var counts = {}, max = 0, res;
for (var v in arr) {
counts[arr[v]] = (counts[arr[v]] || 0) + 1;
if (counts[arr[v]] > max) {
max = counts[arr[v]];
res = arr[v];
}
}
console.log(res + " occurs " + counts[res] + " times");
pls help me to return values not just one...
The result is should like this:
200,300,400
.
pls help thank you!

You have to iterate your counts to find the max occurred result.
var arr = [100,100,200,200,200,300,300,300,400,400,400];
var counts = {}, max = 0, res;
for (var v in arr) {
counts[arr[v]] = (counts[arr[v]] || 0) + 1;
if (counts[arr[v]] > max) {
max = counts[arr[v]];
res = arr[v];
}
}
var results = [];
for (var k in counts){
if (counts[k] == max){
//console.log(k + " occurs " + counts[k] + " times");
results.push(k);
}
}
console.log(results);

Create a Object iterating the arry containing the indexes of most repeated values, like below
var arr = [100,100,200,200,200,300,300,300,400,400,400];
valObj = {}, max_length = 0, rep_arr = [];
arr.forEach(function(el,i){
if(valObj.hasOwnProperty(el)){
valObj[el] += 1;
max_length = (valObj[el] > max_length) ? valObj[el] : max_length
}
else{
valObj[el] = 1;
}
});
Object.keys(valObj).forEach(function(val){
(valObj[val] >= max_length) && (rep_arr.push(val))
});
console.log(rep_arr);
After the object is created with key as array value and value as array indexes of that value, you can play/parse that. Hope this helps.

Iterating an array using for..in is not a good idea. Check this link for more information.
Hopefully below snippet will be useful
var arr = [100, 100, 200, 200, 200, 300, 300, 300, 400, 400, 400];
//Use a reduce fuction to create an object where 100,200,300
// will be keys and its value will the number of times it has
//repeated
var m = arr.reduce(function(i, v) {
if (i[v] === undefined) {
i[v] = 1
} else {
i[v] = i[v] + 1;
}
return i;
}, {});
// Now get the maximum value from that object,
//getMaxRepeated will be 3 in this case
var getMaxRepeated = Math.max(...Object.values(m));
//An array to hold elements which are repeated 'getMaxRepeated' times
var duplicateItems = [];
// now iterate that object and push the keys which are repeated
//getMaxRepeated times
for (var keys in m) {
if (m[keys] === getMaxRepeated) {
duplicateItems.push(keys)
}
}
console.log(duplicateItems)

The following would do the trick assuming that all items in arr are numbers:
//added some numbers assuming numbers are not sorted
var arr = [300,400,200,100,100,200,200,200,300,300,300,400,400,400];
var obj = arr.reduce(//reduce arr to object of: {"100":2,"200":4,"300":4,"400":4}
(o,key)=>{//key is 100,200, ... o is {"100":numberOfOccurrences,"200":numberOf...}
o[key] = (o[key])?o[key]+1:1;
return o;
},
{}
);
// obj is now: {"100":2,"200":4,"300":4,"400":4}
//create an array of [{key:100,occurs:2},{key:200,occurs:4}...
var sorted = Object.keys(obj).map(
key=>({key:parseInt(key),occurs:obj[key]})
)//sort the [{key:100,occurs:2},... by highest occurrences then lowest key
.sort(
(a,b)=>
(b.occurs-a.occurs===0)
? a.key - b.key
: b.occurs - a.occurs
);
console.log(
sorted.filter(//only the highest occurrences
item=>item.occurs===sorted[0].occurs
).map(//only the number; not the occurrences
item=>item.key
)
);

Try as following ==>
function getDuplicate( arr ){
let obj = {}, dup = [];
for(let i = 0, l = arr.length; i < l; i++){
let val = arr[i];
if( obj[val] /**[hasOwnProperty]*/ ) {
/**[is exists]*/
if(dup.find(a => a == val) ) continue;
/**[put Unique One]*/
dup.push(val);
continue;
};
/**[hold for further use]*/
obj[val] = true;
}
return dup;
};
Use ==>
getDuplicate([100,100,200,200,200,300,300,300,400,400,400]);

Try the following:
var candles = [100,100,200,200,200,300,300,300,400,400,400];
let tempArray = {}
for (let index = 0; index <= (candles.length - 1); index++) {
let valueToCompare = candles[index];
if (tempArray[valueToCompare]) {
tempArray[valueToCompare] = tempArray[valueToCompare] + 1;
} else {
tempArray[valueToCompare] = 1;
}
}
let highestValue;
Object.values(tempArray).forEach(item => {
if (highestValue === undefined) highestValue = item;
if (highestValue < item) highestValue = item;
});
console.log(highestValue);

Push different object in an array with a for loop

I have an element structured like this:
Element ->
[{values: arrayOfObject, key:'name1'}, ... ,{values: arrayOfObjectN, key:'nameN'}]
arrayDiObject -> [Object1, Object2, ... , ObjectN] //N = number of lines in my CSV
Object1 -> {x,y}
I have to take data from a big string:
cityX#substanceX#cityY#substanceY#
I thought to make it this way, but it seems like it pushes always in the same array of objects. If I put oggetto = {values: arrayDateValue, key: key}; inside the d3.csv function, instead if I put outside the function it add me only empty objects.
Here is my code:
var final = new Array();
var oggetto;
var key;
function creaDati() {
var newdate;
var arrayDateValue = new Array();
var selString = aggiungiElemento().split("#");
//selString is an array with selString[0]: city, selString[1]: substance and so on..
var citySelected = "";
var substanceSelected = "";
for (var i = 0; i < selString.length - 1; i++) {
if (i % 2 === 0) {
citySelected = selString[i];
} else if (i % 2 !== 0) {
substanceSelected = selString[i];
key = citySelected + "#" + substanceSelected;
d3.csv("/CSV/" + citySelected + ".csv", function(error, dataset) {
dataset.forEach(function(d) {
arrayDateValue.push({
x: d.newdate,
y: d[substanceSelected]
});
});
});
oggetto = {
values: arrayDateValue,
key: key
};
arrayDateValue = [];
final.push(oggetto);
}
}
}
Any idea ?

First you should make the if statement for the city and then for the key, which you seem to be doing wrong since you want the pair indexes to be the keys and the not pair to be the city, and you are doing the opposite. And then you need to have the d3.csv and push the objects outside of the if statement, otherwise in your case you are just adding elements with citySelected="".
Try something like :
for(var i = 0; i < selString.length -1; i+=2){
cittySelected = selString[i];
substanceSelected = selString[i+1];
key = citySelected + "#" + substanceSelected;
d3.csv("/CSV/"+citySelected+".csv", function(error, dataset){
dataset.forEach(function(d){
arrayDateValue.push({x: d.newdate, y: d[substanceSelected]});
});
});
oggetto = {values: arrayDateValue, key: key};
arrayDateValue = [];
final.push(oggetto);
}
It's is not the best way to do it, but it is clearer that what you are following, i think.

In the if(i % 2 == 0) { citySelected = ... } and else if(i % 2 !== 0) { substanceSelected = ... } citySelected and substanceSelected will never come together.
The values should be in one statement:
if(...) { citySelected = ...; substanceSelected = ...; }
The string can be splitted into pairs
city1#substance1, city2#substance2, ...
with a regex (\w{1,}#\w{1,}#).
Empty the arrayDateValue after the if-statement.
Hint:
var str = "cityX#substanceX#cityY#substanceY#";
function createArr(str) {
var obj = {};
var result = [];
var key = "";
// '', cityX#substanceX, '', cityYsubstanceY
var pairs = str.split(/(\w{1,}#\w{1,}#)/g);
for (var i = 0; i < pairs.length; i++) {
if(i % 2 !== 0) {
key = pairs[i];
// d3 stuff to create values
obj = {
// Values created with d3 placeholder
values: [{x: "x", y: "y"}],
// Pair
key: key
};
result.push(obj);
}
// Here should be values = [];
}
return result;
}
var r = createArr(str);
console.log(r);

May be you can do like this;
var str = "cityX#substanceX#cityY#substanceY",
arr = str.split("#").reduce((p,c,i,a) => i%2 === 0 ? p.concat({city:c, key:a[i+1]}) : p,[]);
console.log(JSON.stringify(arr));

RESOLVED-
The problem is about d3.csv which is a asynchronous function, it add in the array when it finish to run all the other code.
I make an XMLHttpRequest for each csv file and it works.
Hope it helps.

Count in an array the number for each same value

My function is
var MyArray= [];
$('input:checked').each(function(index) {
MyArray= ($(this).attr('id') + ":" + $(this).val()).length;
});
My array is
Array [ "1:R1", "2:R2", "3:R3", "4:R1" ]
I would like to count the differents values and to get this object
Object {R1:2, R2:1, R3:1}

Instead of putting the values in an array and then get the values out of the array to process them and create an object, put them in the object to start with:
var map = {};
$('input:checked').each(function() {
var key = $(this).val();
if (key in map) {
map[key]++;
} else {
map[key] = 1;
}
});
Demo: http://jsfiddle.net/Guffa/0a35c6yp/

You can convert your var with this code :
var arr = [ "1:R1", "2:R2", "3:R3", "4:R1" ];
var obj = {};
for(var i=0, l=arr.length; i<l; i++) {
var parts = arr[i].split(':');
if(parts.length > 1) {
if(!obj[parts[1]]) {
obj[parts[1]] = 0;
}
obj[parts[1]]++
}
}
console.log(obj)
Or create directly the correct object :
var obj = {};
$('input:checked').each(function (index) {
var key = $(this).val();
if (!obj[key]) {
obj[key] = 0;
}
obj[key]++
});

Use a regex to capture the correct portion of the string, and add them as keys to the object, incrementing the value if it already exists:
var regex = /\d+:(R\d+)/
var obj = {};
arr.forEach(function (el) {
var key = el.match(regex)[1];
if (!obj[key]) obj[key] = 0;
obj[key]++;
});
DEMO

You could try something like that:
Write your Array into a Map and step up your value each time your map already knows the key.
for(var i = 0; i < myArray.length; i++){
var entry = myArray[i];
var key = entry.split(":")[1];
if(myMap.has(key))
myMap.set(key, myMap.get(key) + 1);
else
myMap.set(key, 1);
}
DEMO

String split and count the number of occurrences and also

I have a string
var stringIHave = "Java$$Java$$jQuery$$Java$$jQuery$$Java$$Java$$Java$$Hibernate$$Java$$Java$$Spring$$Instagram$$jQuery$$jQuery$$";
How to get the count of the number of occurrences of each entry, The occurrence I get, is from a JSON like Java = 8 and etc...

First of all you need to split your srting to array:
var keywordsArr = stringIHave.split( '$$' );
then you need to have an object for example to store counts:
var occur = {};
and then just create simple for loop to count all occurrences:
for( var i = 0; i < keywordsArr.length; i++ ) {
occur[ keywordsArr[ i ] ] = ( occur[ keywordsArr[ i ] ] || 0 ) + 1;
}
now your object occur will have names as keys and count as values.
See jsFiddle demo.
Also as you have at end of your string $$ you maybe will need to remove last item from keywordsArr so just do after split function call:
keywordsArr.pop();
See demo without last element.
So final code will be like:
var stringIHave = "Java$$Java$$jQuery$$Java$$jQuery$$Java$$Java$$Java$$Hibernate$$Java$$Java$$Spring$$Instagram$$jQuery$$jQuery$$",
keywordsArr = stringIHave.split( '$$' ),
occur = {};
keywordsArr.pop();
for( var i = 0; i < keywordsArr.length; i++ ) {
occur[ keywordsArr[ i ] ] = ( occur[ keywordsArr[ i ] ] || 0 ) + 1;
}
for( var key in occur ) {
document.write( key + ' - ' + occur[key] + '<br/>' );
} ​

I'd suggest the following:
function stringCount(haystack, needle) {
if (!needle || !haystack) {
return false;
}
else {
var words = haystack.split(needle),
count = {};
for (var i = 0, len = words.length; i < len; i++) {
if (count.hasOwnProperty(words[i])) {
count[words[i]] = parseInt(count[words[i]], 10) + 1;
}
else {
count[words[i]] = 1;
}
}
return count;
}
}
console.log(stringCount("Java$$Java$$jQuery$$Java$$jQuery$$Java$$Java$$Java$$Hibernate$$Java$$Java$$Spring$$Instagram$$jQuery$$jQuery$$", '$$'));
​
JS Fiddle demo.
References:
Object.hasOwnProperty().
parseInt().
String.split().

It's not entirely clear what final objective is. Following creates an object from string that looks like
Object created:
{
"Java": 8,
"jQuery": 4,
"Hibernate": 1,
"Spring": 1,
"Instagram": 1
}
JS:
var str = 'Java$$Java$$jQuery$$Java$$jQuery$$Java$$Java$$Java$$Hibernate$$Java$$Java$$Spring$$Instagram$$jQuery$$jQuery$$';
var arr = str.split('$$')
var obj = {};
for (i = 0; i < arr.length; i++) {
if (arr[i] != '') {
if (!obj[arr[i]]) {
obj[arr[i]] = 0;
}
obj[arr[i]]++;
}
}
You can loop over the object to get all values or simply look up one value
var jQueryOccurences= obj['jQuery'];
DEMO: http://jsfiddle.net/25hBV/1/

Now a days you can do
const str = "Java$$Java$$jQuery$$Java$$jQuery$$Java$$Java$$Java$$Hibernate$$Java$$Java$$Spring$$Instagram$$jQuery$$jQuery$$";
var result = str.split("$$").reduce(function(acc, curr) {
curr && (acc[curr] = (acc[curr] + 1) || 1);
return acc
}, {});
console.log(result);

Split the string into an array, and putting the array into an object takes care of duplicates and counts occurences as key/value pairs in the object, see fiddle!
var stringIHave = "Java$$Java$$jQuery$$Java$$jQuery$$Java$$Java$$Java$$Hibernate$$Java$$Java$$Spring$$Instagram$$jQuery$$jQuery$$",
s = stringIHave.split('$$');
obj = {};
for (var i=s.length; i--;) {
obj[s[i]] = (s[i] in obj) ? obj[s[i]]+1 : 1;
}
// obj.Java == 8
FIDDLE

If you want it short and sweet:
// variable declarations
var arParts = stringIHave.match(/\w+/g),
result = {},
i = 0,
item;
// Copy the array to result object
while (item = arParts[i++]) result[item] = (result[item] || 0 ) + 1;
demo

How to convert an x-www-form-urlencoded string to JSON?

Exampple of application/x-www-form-urlencoded string
CorrelationId=1&PickedNumbers%5B%5D=1&PickedNumbers%5B%5D=2&PickedNumbers%5B%5D=3&PickedNumbers%5B%5D=4
Into JSON
var gamePlayData = {
CorrelationId: gameId,
PickedNumbers: ["1","2","3","4"]
};

This is a core module of Node.js now: https://nodejs.org/api/querystring.html#querystring_querystring_parse_str_sep_eq_options
var qs = require('querystring')
var json = qs.parse('why=not&sad=salad')
// { why: 'not', sad: 'salad' }
Works with encoded characters too:
var json2 = qs.parse('http%3A%2F%2Fexample.com&sad=salad')
// { url: 'http://example.com', sad: 'salad' }

I've been dealing with this recently: I had to parse data that could contain objects nested up to 5 levels deep. I needed the code to be able to deal with both rather complex data, but not fail to decode a URI as simple as id=213.
I spent quite some time on google, trying to find a (semi-)elegant solution to this problem, and this question kept showing up. Since it gets 1 view/day (give or take) I've decided to post my solution here, hope it helps someone out:
function form2Json(str)
{
"use strict";
var obj,i,pt,keys,j,ev;
if (typeof form2Json.br !== 'function')
{
form2Json.br = function(repl)
{
if (repl.indexOf(']') !== -1)
{
return repl.replace(/\](.+?)(,|$)/g,function($1,$2,$3)
{
return form2Json.br($2+'}'+$3);
});
}
return repl;
};
}
str = '{"'+(str.indexOf('%') !== -1 ? decodeURI(str) : str)+'"}';
obj = str.replace(/\=/g,'":"').replace(/&/g,'","').replace(/\[/g,'":{"');
obj = JSON.parse(obj.replace(/\](.+?)(,|$)/g,function($1,$2,$3){ return form2Json.br($2+'}'+$3);}));
pt = ('&'+str).replace(/(\[|\]|\=)/g,'"$1"').replace(/\]"+/g,']').replace(/&([^\[\=]+?)(\[|\=)/g,'"&["$1]$2');
pt = (pt + '"').replace(/^"&/,'').split('&');
for (i=0;i<pt.length;i++)
{
ev = obj;
keys = pt[i].match(/(?!:(\["))([^"]+?)(?=("\]))/g);
for (j=0;j<keys.length;j++)
{
if (!ev.hasOwnProperty(keys[j]))
{
if (keys.length > (j + 1))
{
ev[keys[j]] = {};
}
else
{
ev[keys[j]] = pt[i].split('=')[1].replace(/"/g,'');
break;
}
}
ev = ev[keys[j]];
}
}
return obj;
}
I've tested it, with data like the string below (4 levels deep):
str = "id=007&name[first]=james&name[last]=bond&name[title]=agent&personalia[occupation]=spy&personalia[strength]=women&personalia[weakness]=women&tools[weapons][close][silent]=garrot&tools[weapons][medium][silent]=pistol_supressed&tools[weapons][medium][loud]=smg&tools[weapons][far][silent]=sniper&tools[movement][slow]=foot&tools[movement][far]=DBS";
Which neatly returns an object, that, when passed through JSON.stringify comes out like this:
{"id":"007","name":{"title":"agent","first":"james","last":"bond"},"personalia":{"weakness":"women","occupation":"spy","strength":"women"},"tools":{"movement":{"far":"DBS","slow":"foot"},"weapons":{"close":{"silent":"garrot"},"medium":{"silent":"pistol_supressed","loud":"smg"},"far":{"silent":"sniper"}}}}
It passes a JSlint check, when ignoring white space, . and [^...] and accepting ++. All in all, I'd consider that to be acceptable.

You can use qs if you're using node, or browserify.
var qs = require('qs')
var encodedString = "CorrelationId=1&PickedNumbers%5B%5D=1&PickedNumbers%5B%5D=2&PickedNumbers%5B%5D=3&PickedNumbers%5B%5D=4"
console.log(qs.parse(encodedString))
// { CorrelationId: '1', PickedNumbers: [ '1', '2', '3', '4' ] }

the following code should do the trick:
var str = 'CorrelationId=1&PickedNumbers%5B%5D=1&PickedNumbers%5B%5D=2&PickedNumbers%5B%5D=3&PickedNumbers%5B%5D=4';
var keyValuePairs = str.split('&');
var json = {};
for(var i=0,len = keyValuePairs.length,tmp,key,value;i <len;i++) {
tmp = keyValuePairs[i].split('=');
key = decodeURIComponent(tmp[0]);
value = decodeURIComponent(tmp[1]);
if(key.search(/\[\]$/) != -1) {
tmp = key.replace(/\[\]$/,'');
json[tmp] = json[tmp] || [];
json[tmp].push(value);
}
else {
json[key] = value;
}
}

Updated answer for 2022, works both in the browser and in node.
Use URLSearchParams class.
Note: The param name PickedNumbers%5B%5D will turn to be the literal string PickedNumbers[]. You don't need to encode the brackets in order to make it an array
const paramsStr = 'CorrelationId=1&PickedNumbers%5B%5D=1&PickedNumbers%5B%5D=2&PickedNumbers%5B%5D=3&PickedNumbers%5B%5D=4';
const params = new URLSearchParams(paramsStr);
//access a specific param
console.log(params.get('PickedNumbers[]')); // '4'
console.log(params.getAll('PickedNumbers[]')); // ['1','2','3','4']
const o = Object.fromEntries(Array.from(params.keys()).map(k => [k, params.getAll(k).length===1 ? params.get(k) : params.getAll(k)]));
console.log(JSON.stringify(o)); //full object

Here's a pure-JavaScript way to do it. JavaScript frameworks might also help you out with this. EDIT: Just for kicks, I threw in dictionary parsing, too. See the 2nd example.
function decodeFormParams(params) {
var pairs = params.split('&'),
result = {};
for (var i = 0; i < pairs.length; i++) {
var pair = pairs[i].split('='),
key = decodeURIComponent(pair[0]),
value = decodeURIComponent(pair[1]),
isArray = /\[\]$/.test(key),
dictMatch = key.match(/^(.+)\[([^\]]+)\]$/);
if (dictMatch) {
key = dictMatch[1];
var subkey = dictMatch[2];
result[key] = result[key] || {};
result[key][subkey] = value;
} else if (isArray) {
key = key.substring(0, key.length-2);
result[key] = result[key] || [];
result[key].push(value);
} else {
result[key] = value;
}
}
return result;
}
decodeFormParams("CorrelationId=1&PickedNumbers%5B%5D=1&PickedNumbers%5B%5D=2&PickedNumbers%5B%5D=3&PickedNumbers%5B%5D=4");
// => {"CorrelationId":"1","PickedNumbers":["1","2","3","4"]}
decodeFormParams("a%5Bb%5D=c&a%5Bd%5D=e");
// => {"a":{"b":"c","d":"e"}}

Try this->
// convert string to object
str = 'a=6&id=99';
var arr = str.split('&');
var obj = {};
for(var i = 0; i < arr.length; i++) {
var bits = arr[i].split('=');
obj[bits[0]] = bits[1];
}
//alert(obj.a);
//alert(obj.id);
// convert object back to string
str = '';
for(key in obj) {
str += key + '=' + obj[key] + '&';
}
str = str.slice(0, str.length - 1);
alert(str);
Or use this (JQuery) http://api.jquery.com/jQuery.param/

A one-liner:
let s = 'a=1&b=2&c=3';
Object.fromEntries(
s.split('&')
.map(s => s.split('='))
.map(pair => pair.map(decodeURIComponent)))
// -> {a: "1", b: "2", c: "3"}
and if you want repeated parameters to be represented as arrays:
let s = 'a=1&b=2&c[]=3&c[]=4&c[]=5&c[]=6';
s
.split('&')
.map(s => s.split('='))
.map(pair => pair.map(decodeURIComponent))
.reduce((memo, [key, value]) => {
if (!(key in memo)) { memo[key] = value; }
else {
if (!(memo[key] instanceof Array))
memo[key] = [memo[key], value];
else
memo[key].push(value);
}
return memo;
}, {})
// -> {"a":"1","b":"2","c[]":["3","4","5","6"]}

You need the opposite of jQuery.param. One of the options is http://benalman.com/code/projects/jquery-bbq/examples/deparam/

var jsonMessage = "{\"".concat(message.replace("&", "\",\"").replace("=", "\":\"")).concat("\"}");

In typescript, works for me:
Use qs.parse to transform in object ParsedQs.
Use as unknow to implicit type unknow and before force convert to string.
Use JSON.parse to convert an string to object.
It was useful to use validations with Joi.
const payload = JSON.parse(JSON.stringify(qs.parse(request.body) as unknown as string));
Payload (cURL):
--data-urlencode 'notification=123-456123' \
--data-urlencode 'test=123456' \
--data-urlencode 'ajieoajeoa=Lorem ipsum'
Result:
{
notification: '123-456123',
test: '123456',
ajieoajeoa: 'Lorem ipsum'
}

public static void Main()
{
string str ="RESULT=0&PNREF=A10AABBF8DF2&RESPMSG=Approved&AUTHCODE=668PNI&PREFPSMSG=No Rules Triggered&POSTFPSMSG=No Rules Triggered";
var sr = str.Replace("&", "=");
string[] sp = sr.Split('=');
var spl = sp.Length;
int n = 1;
var ss = "{";
for (var k = 0; k < spl; k++)
{
if (n % 2 == 0)
{
if (n == spl)
{
ss += '"' + sp[k] + '"';
}
else
{
ss += '"' + sp[k] + '"' + ",";
}
}
else
{
ss += '"' + sp[k] + '"' + ":";
}
n++;
}
ss += "}";
Console.WriteLine(ss);
}