Array: Merge keys and values, to call as an object - javascript

How to code a pure JS.
To call this content:
var keys = ["height", "width"];
var values = [["12px", "24px"],["127px", "284px"]...];
Into readable referral object:
Simple values_line[1].height
may return
127px
Try this code:
var array = keys.map((el, i) => { return [keys[i], values[i]]; });
But it work only to match key to value One time only.
console.log(array);
// → [["height", "12px"], ["width", "24px"]]
var output = Object.fromEntries(array);
// → {height: "12px", width: "24px"}
console.log(output);
or even
var result = {};
for (var i = 0; i < keys.length; i++)
result[keys[i]] = values[i];
Any idea to create object of full "table" with title/head names?


For each value, map over the keys array to create a tuple of [key, value], then use Object.fromEntries to construct your object.
var keys = ["height", "width"];
var values = [["12px", "24px"],["127px", "284px"]];
var dimensions = values.map(value => (
Object.fromEntries(keys.map((key, index) => ([key, value[index]])))
));
console.log(dimensions);


Iterate over values using Array#map.
At each iteration, create an object from keys using Array#reduce representing key-value pairs, where its values are from the current list according to the index:
const
keys = ["height", "width"],
values = [["12px", "24px"],["127px", "284px"]];
const values_line = values.map(currentValues =>
keys.reduce((acc, key, index) => ({ ...acc, [key]: currentValues[index]}), {})
);
console.log(values_line);
Using for-loops:
const
keys = ["height", "width"],
values = [["12px", "24px"],["127px", "284px"]];
const values_line = [];
for(let i = 0; i < values.length; i++) {
const currentValues = values[i];
const currentObj = {};
for(let j = 0; j < keys.length; j++) {
const key = keys[j];
currentObj[key] = currentValues[j];
}
values_line[i] = currentObj;
}
console.log(values_line);

Related

Remove all anagrams from array

I need find and delete all anagrams from an array. All my attempts give ["bac","art"], but I need ["art"]
const deleteAnagrams = (arr) => {
let obj = {};
for (let i = 0; i < arr.length; i++) {
let sorted = arr[i].toLowerCase().split("").sort().join("");
obj[sorted] = arr[i];
}
return Object.values(obj);
};
console.log(deleteAnagrams(['cab', 'bac', 'art']))

You are actually storing unique strings with the last occurence to the object. But you need to remove duplicates and keep only singel occurences of same sorted strings.
To get the result, you need to filter the values.
const deleteAnagrams = array => {
const object = {};
for (const word of array) {
let sorted = word.toLowerCase().split("").sort().join("");
object[sorted] = sorted in object ? undefined : word;
}
return Object.values(object).filter(Boolean);
};
console.log(deleteAnagrams(['cab', 'bac', 'art']));

how to get a cumulative total array from 3 two dimensional arrays

I have 3 two dimensional arrays as given below which are series data to plot lines on a graph with the key being the timestamp.
const arr1 = [[1641013200000,1881],[1643691600000,38993],[1646110800000,41337],[1648785600000,78856],[1651377600000,117738],[1654056000000,119869],[1656648000000,157799],[1659326400000,196752],[1662004800000,199061],[1664596800000,237034],[1667275200000,239153],[1669870800000,269967]]
const arr2 = [[1641013200000,1302],[1643691600000,3347],[1646110800000,4754],[1648785600000,6948],[1651377600000,9725],[1654056000000,11314],[1656648000000,13787],[1659326400000,16666],[1662004800000,18370],[1664596800000,20876],[1667275200000,22384],[1669870800000,23560]]
const arr3 = [[1643691600000,67350],[1648785600000,134700],[1651377600000,202148],[1654056000000,202270],[1656648000000,269843],[1659326400000,337346],[1662004800000,337470],[1664596800000,404861],[1667275200000,404889],[1669870800000,472239]]
I want to plot another series line which gives the cumulative total of all three arrays values
(Note: if a timestamp is not present in either of the arrays, add the previous index value)
const totalArray = [
[1641013200000,3183],[1643691600000, 109690],[1646110800000, 113441],[1648785600000, 220504],
[1651377600000, 329611],[1654056000000, 333453],[1656648000000, 441429],[1659326400000, 550764],
[1662004800000, 554901],[1664596800000, 662771],[1667275200000, 666426],[1669870800000, 765766]
]
I have tried this, but some values are incorrect due to the timestamp not being present in either one
Approach:
const arr1 = [
[1641013200000, 1881],
[1643691600000, 38993],
[1646110800000, 41337],
[1648785600000, 78856],
[1651377600000, 117738],
[1654056000000, 119869],
[1656648000000, 157799],
[1659326400000, 196752],
[1662004800000, 199061],
[1664596800000, 237034],
[1667275200000, 239153],
[1669870800000, 269967]
];
const arr2 = [
[1641013200000, 1302],
[1643691600000, 3347],
[1646110800000, 4754],
[1648785600000, 6948],
[1651377600000, 9725],
[1654056000000, 11314],
[1656648000000, 13787],
[1659326400000, 16666],
[1662004800000, 18370],
[1664596800000, 20876],
[1667275200000, 22384],
[1669870800000, 23560]
];
const arr3 = [
[1643691600000, 67350],
[1648785600000, 134700],
[1651377600000, 202148],
[1654056000000, 202270],
[1656648000000, 269843],
[1659326400000, 337346],
[1662004800000, 337470],
[1664596800000, 404861],
[1667275200000, 404889],
[1669870800000, 472239]
];
const calculateTotal = () => {
var ret;
for (let a3 of arr3) {
var index = arr1.map(function(el) {
return el[0];
}).indexOf(a3[0]);
console.log(index);
if (index === -1) {
ret = arr1[index][0];
console.log(ret);
}
}
let unsortedArr = arr1.concat(arr2, arr3);
var sortedArray = unsortedArr.sort((a, b) => a[0] - b[0]);
var added = addArray(sortedArray);
console.log("Curent Output: " + JSON.stringify(added));
}
const addArray = (tuples) => {
var hash = {},
keys = [];
tuples.forEach(function(tuple) {
var key = tuple[0],
value = tuple[1];
if (hash[key] === undefined) {
keys.push(key);
hash[key] = value;
} else {
hash[key] += value;
}
});
return keys.map(function(key) {
return ([key, hash[key]]);
});
}
calculateTotal();
Is it possible to achieve this?

In your code there is this:
if (index === -1) {
ret = arr1[index][0];
But that assignment will fail as arr1[-1] is not defined.
Then when you do:
let unsortedArr = arr1.concat(arr2, arr3);
...you end up with an array that does not have the knowledge to use default values (from a previous index) when any of the three arrays has a "missing" time stamp.
I would suggest this approach:
Collect all the unique timestamps (from all arrays) into a Map, and associate arrays to each of those keys: these will be empty initially.
Populate those arrays with the timestamps from the original arrays
Get the sorted list of entries from that map
Fill the "gaps" by carrying forward values to a next array when the corresponding slot is undefined. At the same time sum up these values for the final output.
Here is an implementation:
function mergeArrays(...arrays) {
const map = new Map(arrays.flatMap(arr => arr.map(([stamp]) => [stamp, []])));
arrays.forEach((arr, i) => {
for (const [timeStamp, value] of arr) {
map.get(timeStamp)[i] = value;
}
});
const state = Array(arrays.length).fill(0);
return Array.from(map).sort(([a], [b]) => a - b).map(([timeStamp, arr], i) =>
[timeStamp, state.reduce((sum, prev, j) => sum + (state[j] = arr[j] ?? prev), 0)]
);
}
// Example run
const arr1 = [[1641013200000,1881],[1643691600000,38993],[1646110800000,41337],[1648785600000,78856],[1651377600000,117738],[1654056000000,119869],[1656648000000,157799],[1659326400000,196752],[1662004800000,199061],[1664596800000,237034],[1667275200000,239153],[1669870800000,269967]];
const arr2 = [[1641013200000,1302],[1643691600000,3347],[1646110800000,4754],[1648785600000,6948],[1651377600000,9725],[1654056000000,11314],[1656648000000,13787],[1659326400000,16666],[1662004800000,18370],[1664596800000,20876],[1667275200000,22384],[1669870800000,23560]];
const arr3 = [[1643691600000,67350],[1648785600000,134700],[1651377600000,202148],[1654056000000,202270],[1656648000000,269843],[1659326400000,337346],[1662004800000,337470],[1664596800000,404861],[1667275200000,404889],[1669870800000,472239]];
const result = mergeArrays(arr1, arr2, arr3);
console.log(result);

Push in array only values ​that contain a certain string

I would like only data containing a certain string to be sent from my array to another array
for example
test=something
test1=something
test=testsadsad
If my array contains test=
My new array will be ['something', 'testsadsad']
This is my code.
let data = Object.values(args);
let serializedData = data.join("\n");
let newArray = [];
for (let i = 0; i < data.length; i++) {
if (data[i].includes("test=") === true) {
console.log(data[i])
newArray.push(data[i].split("test="));
}
}

You can modify your logic like this
//simulated data
const data = [
"test=something",
"test1=something",
"test=testsadsad",
]
let newArray = [];
for (let i = 0; i < data.length; i++) {
//`key` is `test` and `value` is `something`
const [key, value] = data[i].split("=") //splitted by `=`
if (key === "test") {
newArray.push(value);
}
}
console.log(newArray)

You are not formatting the data correctly when pushing onto the array.
let data = Object.values(args);
let newArray = [];
for (let i = 0; i < data.length; i++) {
if (data[i].includes("test=") === true) {
console.log(data[i])
// Note It looks like your problem is here
newArray.push(data[i].replace("test=", ''));
}
}

If your input array is data then this will return the desired output:
let output = data
.filter(item => item.includes("test="))
.map(item => item.split("test=")[1])
This filters the array by selecting all items that include test= and then maps each result to the substring after test=.

Information about to Array in JAvascript

I would like to get find elements having same characters but in different order in an array. I made javascript below,is there any way to create Javascript function more basic? Can you give me an idea? Thank you in advance..
<p id="demo"></p>
<script>
const arr1 = ["tap", "pat", "apt", "cih", "hac", "ach"];
var sameChars = 0;
var subArr1 = [];
for(var i = 0; i < arr1.length; i++){
for(var j = i+1; j < arr1.length; j++){
if(!subArr1.includes(arr1[i]) && !subArr1.includes(sortAlphabets(arr1[i]))){
subArr1.push(arr1[i]);
sameChars++;
}
if(sortAlphabets(arr1[i]) == sortAlphabets(arr1[j])){
if(!subArr1.includes(arr1[j])){
subArr1.push(arr1[j]);
}
}
}
}
function sortAlphabets(text1) {
return text1.split('').sort().join('');
};
document.getElementById("demo").innerHTML = sameChars;
</script>

I would just use reduce. Loop over split the string, sort it, join it back. Use it as a key in an object with an array and push the items onto it.
const arr1 = ["tap", "pat", "apt", "cih", "hac", "ach"];
const results = arr1.reduce((obj, str) => {
const key = str.split('').sort().join('');
obj[key] = obj[key] || [];
obj[key].push(str);
return obj;
}, {});
console.log(Object.values(results));

You can get the max frequency value by building a map and getting the max value of the values.
const frequencyMap = (data, keyFn) =>
data.reduce(
(acc, val) =>
(key => acc.set(key, (acc.get(key) ?? 0) + 1))
(keyFn(val)),
new Map());
const groupMap = (data, keyFn) =>
data.reduce(
(acc, val) =>
(key => acc.set(key, [...(acc.get(key) ?? []), val]))
(keyFn(val)),
new Map());
const
data = ["tap", "pat", "apt", "cih", "hac", "ach"],
sorted = (text) => text.split('').sort().join(''),
freq = frequencyMap(data, sorted),
max = Math.max(...freq.values()),
groups = groupMap(data, sorted);
document.getElementById('demo').textContent = max;
console.log(Object.fromEntries(freq.entries()));
console.log(Object.fromEntries(groups.entries()));
.as-console-wrapper { top: 2em; max-height: 100% !important; }
<div id="demo"></div>

Maybe split the code into two functions - one to do the sorting and return a new array, and another to take that array and return an object with totals.
const arr = ['tap', 'pat', 'apt', 'cih', 'hac', 'ach'];
// `sorter` takes an array of strings
// splits each string into an array, sorts it
// and then returns the joined string
function sorter(arr) {
return arr.map(str => {
return [...str].sort().join('');
});
}
// `checker` declares an object and
// loops over the array that `sorter` returned
// creating keys from the strings if they don't already
// exist on the object, and then incrementing their value
function checker(arr) {
const obj = {};
for (const str of arr) {
// All this line says is if the key
// already exists, keep it, and add 1 to the value
// otherwise initialise it with 0, and then add 1
obj[str] = (obj[str] || 0) + 1;
}
return obj;
}
// Call `checker` with the array from `sorter`
console.log(checker(sorter(arr)));
<p id="demo"></p>
Additional documentation
map
Loops and iteration
Spread syntax

how to create json with two array in javascript

I have two json:
I want to create json with those two array;
var __columns = ["Field1", "Field2", "Field3", "Field4"];
var __rows = ["valueField1_1", "valueField2_1", "valueField3_1", "valueField4_1", "valueField1_2", "valueField2_2", "valueField3_2", "valueField4_2", "valueField1_3", "valueField2_3", "valueField3_3", "valueField4_3"];
The thing is that I wanna create something like this
var json = [{
"Field1":"valueField1_1",
"Field2":"valueField2_1",
"Field3":"valueField3_1",
"Field4":"valueField4_1"
},{
"Field1":"valueField1_2",
"Field2":"valueField2_2",
"Field3":"valueField3_2",
"Field4":"valueField4_2"
},{
"Field1":"valueField1_3",
"Field2":"valueField2_3",
"Field3":"valueField3_3",
"Field4":"valueField4_3"
}]

ES6 solution using Array.from and Array#reduce methods.
var __columns = ["Field1", "Field2", "Field3", "Field4"];
var __rows = ["valueField1_1", "valueField2_1", "valueField3_1", "valueField4_1", "valueField1_2", "valueField2_2", "valueField3_2", "valueField4_2", "valueField1_3", "valueField2_3", "valueField3_3", "valueField4_3"];
var res = Array.from({
// generate array with particular size
length: __rows.length / __columns.length
// use map function to generate array element
}, (_, i) => __columns.reduce((obj, e, i1) => {
// define object property based on the index values
obj[e] = __rows[i * __columns.length + i1];
return obj;
// set empty object as initial argument
}, {}));
console.log(res);

function convertToJsonArr(__columns, __rows){
var obj = {};
var arr = [];
var len = __columns.length;
var count = 0;
$.each(__rows , function(key, value){
if(count >= len){
count = 0;
arr.push(obj);
obj = {};
}
obj[__columns[count++]] = value;
})
arr.push(obj);
return arr;
}
you can call like convertToJsonArr(__columns, __rows);

One way to achieve this is using loops
var __columns = ["Field1", "Field2", "Field3", "Field4"];
var __rows = ["valueField1_1", "valueField2_1", "valueField3_1", "valueField4_1", "valueField1_2", "valueField2_2", "valueField3_2", "valueField4_2", "valueField1_3", "valueField2_3", "valueField3_3", "valueField4_3"];
var arr = [];
for(var i = 0; i < __rows.length; i = i + __columns.length){
var tempObj = {};
for(var j = 0; j < __columns.length; ++j){
tempObj[__columns[j]] = __rows[i];
}
arr.push(tempObj);
}
console.log(arr);

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