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I am trying to remove specific elements from an array based on data I'm getting from an API. The API returns an array of objects like this {"videoDate":"07/31/2020","videoTime":"1:00 AM"}. I have an existing array with items that look like this "07/31/2020 1:00 AM". My intention is to check if the existing array contains an item with a string matching both the videoDate and videoTime strings from the object and remove them.
let responseArray = JSON.parse(response);
responseArray.forEach((item) => {
dayArray.forEach((day) => {
if (day.includes(item.videoDate) && day.includes(item.videoTime)) {
let index = dayArray.findIndex(item => item.videoDate && item.videoTime);
dayArray.splice(index, 1);
}
});
});
console.log(dayArray);
The above code flags everything and returns an empty dayArray.
let responseArray = JSON.parse(response);
responseArray.forEach((item) => {
dayArray.forEach((day) => {
if (day.includes(item.videoDate) && day.includes(item.videoTime)) {
// ts-ignore
let index = dayArray.findIndex(item.videoDate && item.videoTime);
dayArray.splice(index, 1);
}
});
});
console.log(dayArray);
The above code throws an error TypeError: 1:00 AM is not a function
response.forEach((item) => {
dayArray.forEach((day) => {
if (day.includes(item.videoDate) && day.includes(item.videoTime)) {
// ts-ignore
let index = dayArray.findIndex(item.videoDate && item.videoTime);
dayArray.splice(index, 1);
}
});
});
console.log(dayArray);
The above code where I'm not parsing the response first returns response.forEach is not a function
Is there a better way to accomplish this?
I edited my previous solution, I believed, what you wanted to do is if the items (date and time) in the array matches any value in the returned object, remove the item from the array.
Test it and give feed back
let response = `[{"videoDate":"07/31/2020","videoTime":"1:00 AM"}]`
let dayArray = ["07/31/2020 1:00 AM"];
let responseArray = JSON.parse(response);
dayArray.forEach((el, i) => {
let item = el.split(/(^[^\s]*)\s/);
item.shift();
responseArray.forEach((obj) => {
let obj_vals = Object.values(obj);
if(obj_vals.indexOf(item[0]) != -1 && obj_vals.indexOf(item[1]) != -1 ) dayArray.splice(i, 1);
}); });
console.log(dayArray)
I would like to know how to filter array of values using javascript
How to seperate the arrays with 'provider-send' and 'provider-receive'
var filterradio = id.filter(function(e){
return e.id.split("-")[0] == "provider-send"
})
var id=["provider-send-credit-transfer", "provider-send-debit-fund","provider-receive-credit-transfer","provider-receive-debit-fund"]
Expected Output:
result_sn: ["provider-send-credit-transfer", "provider-send-debit-fund"]
result_rcn:["provider-receive-credit-transfer","provider-receive-debit-fund"]
If it's always going to be "provider-receive-..." and "provider-send..." then you can do the following to separate them
for (i = 0; i < id.length; i++) {
if (id[i].split("provider-send-").length > 1) {
result_sn.push(id[i]);
} else if (id[i].split("provider-receive-").length > 1) {
result_rcn.push(id[i])
}
}
Try This :
var id = [ "provider-send-credit-transfer", "provider-send-debit-fund","provider-receive-credit-transfer","provider-receive-debit-fund" ] ;
var result_sn = [] , result_rcn = [] ;
for( value of id ) {
var twoWords = value.split('-',2).join('-') ;
if ( twoWords === "provider-send" )
result_sn.push( value ) ;
else if ( twoWords === "provider-receive" )
result_rcn.push( value ) ;
}
console.log( result_sn ) ;
console.log( result_rcn ) ;
Pass 2 as second parameter to split() and then again join() by -. The second parameter to split() specifies the max number of elements in the result array.
var id=["provider-send-credit-transfer", "provider-send-debit-fund","provider-receive-credit-transfer","provider-receive-debit-fund"]
var filterradio = id.filter(function(id){
return id.split("-",2).join('-') === "provider-send"
})
console.log(filterradio)
Using .filter() will require you to write 1 filter for every pattern you want to match have assigned to a variable.
Using .reduce() is recommended and is more easily expandable to support more patterns.
It may look intimidating at first but you're essentially using accumulator as the temporary variable that gets stored and brought forward to each iteration. And each iteration of the array will give you the current iterated value with currentValue.
I've added something-else as an example of adding new pattern.
var id = [
"provider-send-credit-transfer",
"provider-send-debit-fund",
"provider-receive-credit-transfer",
"provider-receive-debit-fund",
"something-else-credit-transfer",
"something-else-debit-fund"
];
const {
'provider-send': result_sn,
'provider-receive': result_rcn,
'something-else': result_ste
} = id.reduce(function(accumulator, currentValue) {
let prefix = currentValue.match(/^\w+-\w+/)[0];
return {...accumulator, [prefix]: (accumulator[prefix] || []).concat(currentValue)}
}, {});
console.log(result_sn);
console.log(result_rcn);
console.log(result_ste);
I suggest using reduce instead of the filter as reduce is used to reduce the array size into a single returned element.
Here I am reducing the array into an object which has two keys result_sn and result_rcn.
var id = ["provider-send-credit-transfer", "provider-send-debit-fund", "provider-receive-credit-transfer", "provider-receive-debit-fund"]
const result = id.reduce((obj, str) => {
if (str.match(/^provider-send/g))
obj['result_sn'].push(str);
else
obj['result_rcn'].push(str);
return obj;
}, {
'result_sn': [],
'result_rcn': []
});
console.log(result)
My Code Scenario is:
var Employees= [{name:"Ram",htno:1245},{name:"mohan",htno:1246},
{name:"madhu",htno:1247},{name:"ranga",htno:1248}]
var seletedEmployees= [{name:"mohan"},{name:"ranga"}];
var employeesdataAfterremoveSelected = [?];
You can store selected employees names in an array and then filter Employees array and check if employee's name is in this array:
var employees= [{name:"Ram",htno:1245},{name:"mohan",htno:1246},{name:"madhu",htno:1247},{name:"ranga",htno:1248}]
var selectedEmployees= ["mohan","ranga"];
var result = employees.filter(emp => selectedEmployees.includes(emp.name));
console.log(result);
To programatically get array of strings instead array of objects, you can use map:
var seletedEmployees= [{name:"mohan"},{name:"ranga"}].map(emp => emp.name);
From the code you have given above i think this might work
$.each(student, function(key, value){
if(matchedvalues.indexOf(value.name) < 0)
{
employeesdataAfterremoveSelected.push(value.name);
}
})
Here is a one liner, decomposed to explain :
// Start by filtering the first array on a condition.
employeesdataAfterremoveSelected = Employees.filter(
// Map the array of selected employees to only return the name
e => seletedEmployees.map(_e => _e.name)
// use the includes function to check if the name is in the array
.includes(e.name)
);
In one line :
employeesdataAfterremoveSelected = Employees.filter(e => seletedEmployees.map(_e => _e.name).includes(e.name));
You can use the filter method, something like below (not tested)
var Employees = [{name:"Ram",htno:1245}, {name:"mohan",htno:1246}]
var SelectedEmployess = [{name:"Ram",htno:1245}]
// filter the items from the invalid list, out of the complete list
var employeesdataAfterremoveSelected = Employees.filter((item.name) => {
return !SelectedEmployess.has(item.name);
})
// get a Set of the distinct, valid items
var validItems = new Set(employeesdataAfterremoveSelected);
You can try this:
var Employees = [{name:"Ram",htno:1245},{name:"mohan",htno:1246},
{name:"madhu",htno:1247},{name:"ranga",htno:1248}]
var seletedEmployees = [{name:"mohan"},{name:"ranga"}];
var employeesdataAfterremoveSelected = Employees.filter(name => {
return (name.name !== seletedEmployees[0].name && name.name !== seletedEmployees[1].name)
})
console.log(employeesdataAfterremoveSelected)
var Employees= [{name:"Ram",htno:1245},{name:"mohan",htno:1246},
{name:"madhu",htno:1247},{name:"ranga",htno:1248}]
var seletedEmployees= [{name:"mohan"},{name:"ranga"}];
var employeesdataAfterremoveSelected = Employees.filter(function(val,index) { console.log(val.name)
return !(seletedEmployees.map(function(e) { return e.name; }).indexOf(val.name));
});
I'm trying to write a vote counting function, I have an array of objects and each object has a property called currentVote which has a userId value. I want to find out which userID has the most votes. Using lodash this is what I got so far:
function countVotes(players) {
return new Promise(function(resolve, reject) {
//votes should be empty, filled it with some sample values
let votes = ['312139659792875521','360445341989863434', '312139659792875521','360445341989863435','1','9999999999999999999999'];
for (let i = 0, j = players.length; i < j; i++) {
votes.push(players[i].currentVote);
}
let tally = _.chain(votes)
.countBy()
.toPairs()
.sortBy(1).reverse()
.map(0)
.value()[0];
resolve(tally);
});
How can I pick a random value IF I have multiple userIds with the same number of votes. At the moment it seems that the smallest ID will always be picked?
Based on your question, I believe your object is as follow, I have used the array method sort to sort the array in descending and picked up the first element. Hope this helps.
let players = [{
"userId":1,
"currentVotes":2220
},
{
"userId":2,
"currentVotes":383830
},
{
"userId":3,
"currentVotes":6894740
},
{
"userId":4,
"currentVotes":6894740
},
{
"userId":5,
"currentVotes":1
}
];
function getHighestVoteByRandowm(players){
let arrSameVotes = [];
let i = 0;
do{
arrSameVotes.push(players[i]);
temp = players[i].currentVotes;
i++;
}while(players[i].currentVotes == temp);
let rndTill = arrSameVotes.length - 1;
let rndVal = Math.round(Math.random() * rndTill);
return arrSameVotes[rndVal];
}
function sortVotes(a,b){
return b.currentVotes - a.currentVotes;
}
let highestVotesPlayer = getHighestVoteByRandowm(players.sort(sortVotes));
console.log(highestVotesPlayer);
You could use _.shuffle and _.first. Maybe something like:
_.chain(votes).countBy()
.groupBy() // added this to get a list of all the ones that have matching vote counts
.toPairs()
.sortBy(0)
.reverse()
.first() // most votes
.last() // get the user ids
.shuffle() // randomize order
.first() // get whatever is first
.value()
I have this 2D array as follows:
var data = [[1349245800000, 11407.273], [1349247600000, 12651.324],
[1349249400000, 11995.017], [1349251200000, 11567.533],
[1349253000000, 11126.858], [1349254800000, 9856.455],
[1349256600000, 8901.779], [1349258400000, 8270.123],
[1349260200000, 8081.841], [1349262000000, 7976.148],
[1349263800000, 7279.652], [1349265600000, 6983.956],
[1349267400000, 7823.309], [1349269200000, 6256.398],
[1349271000000, 5487.86], [1349272800000, 5094.47],
[1349274600000, 4872.403], [1349276400000, 4168.556],
[1349278200000, 4501.939], [1349280000000, 4150.769],
[1349281800000, 4061.599], [1349283600000, 3773.741],
[1349285400000, 3876.534], [1349287200000, 3221.753],
[1349289000000, 3330.14], [1349290800000, 3147.335],
[1349292600000, 2767.582], [1349294400000, 2638.549],
[1349296200000, 2477.312], [1349298000000, 2270.975],
[1349299800000, 2207.568], [1349301600000, 1972.667],
[1349303400000, 1788.853], [1349305200000, 1723.891],
[1349307000000, 1629.002], [1349308800000, 1660.084],
[1349310600000, 1710.227], [1349312400000, 1708.039],
[1349314200000, 1683.354], [1349316000000, 2236.317],
[1349317800000, 2228.405], [1349319600000, 2756.069],
[1349321400000, 4289.437], [1349323200000, 4548.436],
[1349325000000, 5225.245], [1349326800000, 6261.156],
[1349328600000, 8103.636], [1349330400000, 10713.788]]
How do I get the index of value 1349247600000 in the array? I have tried $.inArray(1349247600000, data) but as expected this fails. Is there any other way or do I have to iterate over each? I am reluctant to add another loop to my process
This is a typical performance versus memory issue. The only way (that I know of) to avoid looping through the array, would be to maintain a second data structure mapping the timestamps to the index of the array (or whatever data might needed).
So you would have
var data = [
[1349245800000, 11407.273],
[1349247600000, 12651.324],
// ...
[1349330400000, 10713.788]
];
// the timestamps pointing at their respective indices
var map = {
'1349245800000': 0, // 0
'1349247600000': 1, // 1
// ...
'1349330400000': 42, // n - 1 (the length of the data array minus one)
}
This way, you use more memory, but have a constant lookup time when needing the index of the item in the array that a given timestamp belongs to.
To get the index of a given timestamp do:
map['1349247600000']; // resulting in 1 (e.g.)
If the data structure is dynamically changed, you would of course need to maintain the map data structure, but depending on the context in which you need the lookup, the constant time lookup can potentially be a real time saver compared to a linear time lookup.
I think you need a different data structure.
Try using a standard javascript object ({ key: value } - sometimes called a map or dictionary) to express your data. Looking up keys in an object is highly optimized (using something called hash tables).
If the index in your array has any meaning, store it as a property (typically named _id).
Ideally you should be using an object for this:
var data = {
'1349247600000': 12651.324
}
which you can access like:
data['1349247600000'];
However, this might be a nice solution (IE9 and above) in the meantime:
var search = 1349247600000;
function findIndex(data, search) {
var filter = data.filter(function (el, i) {
el.unshift(i);
return el[1] === search;
});
return filter[0][0];
}
console.log(findIndex(data, search));
fiddle : http://jsfiddle.net/CLa56/
var searchElement = 1349251200000;
var strdata = data.toString();
var newdata = eval("[" + strdata + "]");
var indexsearch = newdata.indexOf(searchElement);
var index = indexsearch/2; // 2 because array.length = 2
var params = {id: 1349251200000, index: -1};
data.some(function (e, i) {
if (e[0] === this.id) {
this.index = i;
return true;
}
}, params);
console.log(params.index);
jsfiddle
MDN|some Array Method
Note that this solution stops iterating after found, not necessarily over the entire array, so could be much faster for large arrays.
What about a custom cross browser solution ?
function findIndexBy(a, fn) {
var i = 0, l = a.length;
for (; i < l; i++) {
if (fn(a[i], i)) {
return i;
}
}
return -1;
}
Usage :
var list = [[1],[2],[3]], idx;
// idx === 1
idx = findIndexBy(list, function (item, i) {
return item[0] === 2;
});
// idx === -1
idx = findIndexBy(list, function (item, i) {
return item[0] === 4;
});