I am trying to display the contents of an array in a more readable way, this is the array:
["malevolent", "pariah", "judicious", "pariah", "judicious"]
I'm simply adding that array to an HTML element to display it, but I want to display it like this:
malevolent, pariah x 2, judicious x2
How would I do this?
It's quite simple actually:
var myArray = new Array("a", "b", "c", "b", "a");
var newObject = {};
// Iterate over the array
for(var i = 0; i < myArray.length; i++){
// If the new object already contains the key (e.g. a, b, or c), increment value by one
if(myArray[i] in newObject){
newObject[myArray[i]]++;
} else {
// Otherwise add a key (e.g. a, b, or c) to the object and assign 1 to it (first occurence)
newObject[myArray[i]] = 1;
}
}
// Write the resulting object to console
window.console && console.log(newObject);
newObject contains a list of keys (a,b,c) and values (number of occurrences of each key). You can than use that data to output it in any format you like, but that's left up to you as an excercise.
You can try the following:
var myArray = ["malevolent", "pariah", "judicious", "pariah", "judicious"];
var resultArray = [];
var countArray = [];
for(index in myArray) {
var element = myArray[index];
var isInArray = resultArray.indexOf(element);
if(isInArray !== -1) {
var tmpCnt = countArray[isInArray];
tmpCnt++;
countArray[isInArray] = tmpCnt;
} else {
resultArray.push(element);
countArray.push(1);
}
}
console.log(resultArray);
console.log(countArray);
Felix Kling provided a Link to an answer on how to count your elements. I just shamelessly use the reduce method described there and then just iterate over the object to build a string.
var a = ["malevolent", "pariah", "judicious", "pariah", "judicious"].reduce(function (acc, curr) {
if (typeof acc[curr] == 'undefined') {
acc[curr] = 1;
} else {
acc[curr] += 1;
}
return acc;
}, {});
var out = "";
for (var k in a) {
out += k + " x " + a[k] + "; ";
}
console.log(out);
try this
var arr = new Array("malevolent", "pariah", "judicious", "pariah", "judicious");
var new_arr1 = new Array(); // for containing distinct values like pariah
var new_arr2 = new Array(); // for containing distinct values count like 2 for pariah
// both will be on same index in new_arr1 and new_arr2
for(var i=0; i<arr.length; i++)
{
// fetch every value of arr
var indx = $.inArray(arr[i], new_arr1); // check value is exists in new_arr1 and get index
if(indx > -1) // values exists in new_arr1
{
var v = new_arr2[indx]+1; // increment the previous count +1
new_arr2[indx] = v; // update it on the index of new_arr2
}
else
{
// if value not in new_arr1 means the value comes first time
var l = new_arr1.length;
new_arr1[l] = arr[i]; // insert value in new_arr1
new_arr2[l] = 1; // initate count 1 for the same index of new value in new_arr2
}
}
// now new_arr1 will contains the distinct values
// and new_arr2 contains the count for distinct values
// eg new_arr1[0] = 'malevolent';
// new_arr2[0] = 1;
// new_arr1[1] = 'pariah';
// new_arr2[1] = 2;
// now you can fetch distinct values and their count like given below
for(var i=0; i<new_arr1.length; i++)
{
var str = new_arr1[i]+" X "+new_arr2[i];
alert(str);
}
See FIDDLE
Related
Explanation of Desired Results
My source is over 30,000 lines of very structured text with incrementing front numbers followed by incrementing back numbers and separated by a colon. Stripping out the non-essentials, I am left with the following sourceArray, truncated for convenience :)
sourceArray = ["001:001", "001:002", "001:003",
"002:001", "002:002",
"003:001", "003:002"];
I am trying to count how many back numbers for each front number and push that to an array. In pseudocode, my final results should look like this:
myArray[totalNumberOf_001_Items, totalNumberOf_002_Items, totalNumberOf_003_Items]
Which in my simple example should give me a final value of:
[3, 2, 2]
Problem and Question
My for loop ends at the end of my data and I am therefore one element short in my array.
How do I make an "extra pass" through the loop or is there another way to get the final element pushed to my array?
var sourceArray = ["001:001", "001:002", "001:003",
"002:001", "002:002",
"003:001", "003:002"
];
var myArray = [];
var frontCounter = 1;
var backCounter = 1;
for (var i = 0; i < sourceArray.length; i++) {
var text = sourceArray[i];
var front = text.substr(0, 3);
front = Number(front);
var back = text.substr(4, 3);
back = Number(back);
if (front == frontCounter) {
backCounter++;
} else {
myArray.push(backCounter - 1);
backCounter = 2;
frontCounter++;
}
}
console.log(myArray); // result [3, 2]
You could use an object like below to keep track of how many times the the piece of text appear, the text would be the keys and as value the number of times they appear. From that you can build you array
var sourceArray = ["001:001", "001:002", "001:003",
"002:001", "002:002",
"003:001", "003:002"];
var frontEncounters = {};
function updateFrontEncounters(frontEncounters, front){
var keys = Object.keys(frontEncounters);
if(keys.indexOf(front) == -1)
{
frontEncounters[front] = 1;
}
else
{
frontEncounters[front] += 1;
}
}
for(var item in sourceArray){
var text = sourceArray[item];
var front = text.substr(0, 3);
var back = text.substr(4, 3);
updateFrontEncounters(frontEncounters, front);
}
var keys = Object.keys(frontEncounters);
var myArr = [];
for(var key in keys)
{
myArr.push(frontEncounters[keys[key]])
}
console.log(myArr);
Use an object to store the "front" numbers along with their count.
for (var i = 0; i < sourceArray.length; i++) {
var num = sourceArray[i].slice(0,3);
counts[num] = counts[num] ? counts[num]+1 : 1;
}
Once done, you can very easily convert that to an array:
var result = Object.keys(counts).map(function (key) {
return counts[key];
});
With ES-2017, it is even easier:
var result = Object.values(counts)
Working Snippet:
var sourceArray = ["001:001", "001:002", "001:003",
"002:001", "002:002",
"003:001", "003:002"];
var counts = {};
for (var i = 0; i < sourceArray.length; i++) {
var num = sourceArray[i].slice(0,3);
counts[num] = counts[num] ? counts[num]+1 : 1;
}
console.log(counts);
var result = Object.keys(counts).map(function (key) {
return counts[key];
});
console.log(result);
// ES-2017
//console.log(Object.values(counts));
Here's an alternative that you can use so that you don't have to go through the entire source of lines (30,000) . Use a while loop so that you can break as soon as you reach a 0; use Map to store the unique number by making the index/frontnumber the key and make its value an object that serves as a counter to keep track of it's total. If the key exists, update the total; if it doesn't, create a new counter object. Then just return the Map by transforming it into the desired array by map'ing it to an array with only the totals.
var sourceArray = ["001:001", "001:002", "001:003",
"002:001", "002:002",
"003:001", "003:002"
];
function getTotal(sourceArray) {
let count = new Map();
let update = item => count.get(item).total++;
let create = item => count.set(item, {total: 1});
const getItem = index => {
let text = sourceArray[index];
return text.substr(0, 3);
}
let index = -1;
let start = 0;
while (index != 0 && start < sourceArray.length) {
index = getItem(start++);
count.has(index) ? update(index) : create(index);
}
return [...count.values()].map(item => item.total);
}
console.log(getTotal(sourceArray));
I have two arrays:
var arr1 = [1,2,3,4,5]
var arr2 = [7,1,8,2,12,3,4,28,5]
I need to go through arr2 looking for matches to arr1, but it has to be in order (1,2,3,4,5). As you can see in arr2, the order does exists, but there are some numbers in between.
[7,1,8,2,12,3,4,28,5]
I have about 50 arrays similar to arr2, so I need to look through each one, and when I find a match, push it out to a "results" object. Small issue though is that some arrays will not have the entire match, may only have 1,2,3 or any variation of the search. Also, if the array I'm searching in is NOT in order, (IE: starts at 2,3,4) skip over it entirely.
The idea is to loop through these arrays, and when I find a match, add a count to the results array.
For example, using arr1 as the search, go through these arrays:
[7,1,8,2,12,3,4,28,5],
[7,1,8,2,12,3,4],
[7,8,1,2],
[1,2,3]
and have a result that looks like this (a dictionary of what was searched for, and a count of what was found) :
{1:4, 2:4, 3:3, 4:2, 5:1}
I tried doing a bunch of for-loops, but I can't figure out how to skip over a number that I'm not looking for, and continue onto the next iteration, while saving the results into a dictionary object.
let list = [[7,1,8,2,12,3,4,28,5], [7,1,8,2,12,3,4], [7,8,1,2], [1,2,3]];
let search = [1, 2, 3, 4, 5];
// Initialize result with zeros:
let result = search.reduce((result, next) => {
result[next] = 0;
return result;
}, {});
// Increment result for items found:
list.forEach(array => {
for (let i = 0, j = 0; i < array.length && j < search.length; ++i) {
if (array[i] == search[j]) {
++result[search[j]];
++j;
}
}
});
console.log(result);
Essentially this:
var needle = [1,2,3,4,5]
var collection = [[7,1,8,2,12,3,4,28,5], [7,1,8,2,12,3,4], [7,8,1,2], [1,2,3]]
// start with an object
var results = {}
// populate object with zeros
needle.forEach(function (i) { results[i] = 0 })
// define an index to iterate through collection
var i = 0
// define an index to conditionally iterate through "arr1"
var j = 0
// define an index to iterate through collection arrays
var k = 0
// define surrogate for the arrays in the collection
var arr
while (i < collection.length) {
// get collection array
arr = collection[i]
// reset the indices
j = 0
k = 0
while (k < arr.length) {
// if same element on needle is in a collection array
if (needle[j] === arr[k]) {
// save it in an object starting at 1
results[needle[j]]++
j++ // increment needle
}
k++ // increment array in collection
}
i++ // increment collection
}
console.log(results) // {1:4, 2:4, 3:3, 4:2, 5:1}
I hope that helps!
var arr1 = [1,2,3,4,5];
var arr2 = [7,1,8,2,12,3,4,28,5];
function givenTwoArrays(a,b, obj){
var obj = obj || {};
var cond = true;
function otherMatch(indexFound,elementFound){
var indexOnA = a.indexOf(elementFound);
return a.some(function(ele, idx){
if(idx > indexOnA)
return b.some(function(bele,bidx){
return ele == bele && bidx < indexFound;
});
});
}
a.map(function(aele,idx){
if(cond){
var indexFound = b.findIndex(function(bele){
return aele == bele;
});
if(typeof indexFound !== 'undefined'){
if(!otherMatch(indexFound,aele)){
if(typeof obj[aele] !== 'undefined')
obj[aele]++;
else{
obj[aele] = 1;
}
} else {
cond = false;
}
}else
cond = false;
}
});
return obj;
}
console.log("first pass");
console.log(givenTwoArrays(arr1,arr2))
console.log("second pass");
console.log(givenTwoArrays(arr1,arr2,{
"1": 1,
"2": 1,
"3": 1,
"4": 1,
"5": 1
}));
I think this will work, just need to add a little recursion!
var orign = [1,2,3,4,5];
var arr = [[7,1,8,2,12,3,4,28,5], [7,1,8,2,12,3,4], [7,8,1,2], [1,2,3]];
//temp result
var arrTmp = [];
for (var x in arr){
var match = 0;
var mis = 1;
var curIndex = 0;
var cur = orign[curIndex];
var arrTmpX = [];
for(var y in arr[x]){
if(arr[x][y] !== cur){
mis=1;
}else{
//add match after mismatch
arrTmpX.push(cur);
curIndex++
cur = orign[curIndex];
}
}
arrTmp.push(arrTmpX);
}
//calc result
var result = {};
for (var x in orign){
result[orign[x]] = 0;
for(var y in arrTmp){
if(arrTmp[y].length>x)result[orign[x]]++;
}
}
console.log(result);
this works
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.
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
I need to know if one or more duplicates exist in a list. Is there a way to do this without travelling through the list more than once?
Thanks guys for the suggestions. I ended up using this because it was the simplest to implement:
var names = [];
var namesLen = names.length;
for (i=0; i<namesLen; i++) {
for (x=0; x<namesLen; x++) {
if (names[i] === names[x] && (i !== x)) {alert('dupe')}
}
}
Well the usual way to do that would be to put each item in a hashmap dictionary and you could check if it was already inserted. If your list is of objects they you would have to create your own hash function on the object as you would know what makes each one unique. Check out the answer to this question.
JavaScript Hashmap Equivalent
This method uses an object as a lookup table to keep track of how many and which dups were found. It then returns an object with each dup and the dup count.
function findDups(list) {
var uniques = {}, val;
var dups = {};
for (var i = 0, len = list.length; i < len; i++) {
val = list[i];
if (val in uniques) {
uniques[val]++;
dups[val] = uniques[val];
} else {
uniques[val] = 1;
}
}
return(dups);
}
var data = [1,2,3,4,5,2,3,2,6,8,9,9];
findDups(data); // returns {2: 3, 3: 2, 9: 2}
var data2 = [1,2,3,4,5,6,7,8,9];
findDups(data2); // returns {}
var data3 = [1,1,1,1,1,2,3,4];
findDups(data3); // returns {1: 5}
Since we now have ES6 available with the built-in Map object, here's a version of findDups() that uses the Map object:
function findDups(list) {
const uniques = new Set(); // set of items found
const dups = new Map(); // count of items that have dups
for (let val of list) {
if (uniques.has(val)) {
let cnt = dups.get(val) || 1;
dups.set(val, ++cnt);
} else {
uniques.add(val);
}
}
return dups;
}
var data = [1,2,3,4,5,2,3,2,6,8,9,9];
log(findDups(data)); // returns {2 => 3, 3 => 2, 9 => 2}
var data2 = [1,2,3,4,5,6,7,8,9];
log(findDups(data2)); // returns empty map
var data3 = [1,1,1,1,1,2,3,4];
log(findDups(data3)); // returns {1 => 5}
// display resulting Map object (only used for debugging display in snippet)
function log(map) {
let output = [];
for (let [key, value] of map) {
output.push(key + " => " + value);
}
let div = document.createElement("div");
div.innerHTML = "{" + output.join(", ") + "}";
document.body.appendChild(div);
}
If your strings are in an array (A) you can use A.some-
it will return true and quit as soon as it finds a duplicate,
or return false if it has checked them all without any duplicates.
has_duplicates= A.some(function(itm){
return A.indexOf(itm)===A.lastIndexOf(itm);
});
If your list was just words or phrases, you could put them into an associative array.
var list=new Array("foo", "bar", "foobar", "foo", "bar");
var newlist= new Array();
for(i in list){
if(newlist[list[i]])
newlist[list[i]]++;
else
newlist[list[i]]=1;
}
Your final array should look like this:
"foo"=>2, "bar"=>2, "foobar"=>1