Reduce refers to the operation, where a array of items is reduced to a single value. Use with language tag like [c++], [google-sheets-formula]. Do NOT use alone.
Questions tagged [reduce]
3548 questions
1
vote
1 answer
Promise not resolving before returning
I am having a hard time figuring out how promises work. I have the following code that I am executing iterate through an array.
runOpts.automationResults.reduce(function (p, val) {
return p.then(function () {
return …
Christine Edwards
- 99
- 8
1
vote
3 answers
Using reduce to get a sum of object values, but the answer is a few decimals short (JS)
I have the following code:
function checkCashRegister(price, cash, cid) {
// Move cid into an object
var cashReg = cid.reduce(function(prev, curr) {
prev[curr[0]] = curr[1];
return prev;
}, {});
// Total money…
Mikael Törnwall
- 77
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vote
1 answer
Create a new array of objects building on previous values
I'm trying to build an array of objects out of another array of objects:
const items = [
{
id: 'thing-1',
size: {
height: 50
},
},
{
id: 'thing-2',
size: {
height: 100
}
},
{
…
Matt Coady
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vote
2 answers
JS: Counting Elements in Array -> Returning Array of Arrays
I have an array which looks like this:
fruits = ['Apple', 'Apple', 'Peach', 'Apple', 'Banana', 'Pear', 'Apple', 'Banana', 'Peach'];
Now I'm trying to count the containing elements to get a result which looks like this:
[
['Apple', 4],
['Peach',…
Nibor
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4 answers
Reduce array with javascript
I have an array like this :
myArray = [40, 40, 40, 40, 40, 80, 40, 40, 40, 40, 40, 40, 40, 40, 80, 40, 40, 40, 40, 40, 40, 40, 40]
I would like to reduce it like this :
myNewArray =[40, 80, 40, 80,40]
Manheman
- 39
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1
vote
3 answers
Javascript reduce function error
I am trying to play with the Reduce function in JavaScript. What I am trying to achieve can be easily done via the filter function but I am trying to do it via Reduce.
I am trying to retrieve all the people where the age is greater or equal to 18…
Manish
- 21
- 5
1
vote
1 answer
How to reduce a compact buffer in scala?
Here is my RDD:
scala> grouped_final_resultMap.first
res20: (String, Iterable[Float]) = (2014-02-01,CompactBuffer(239.96, 129.99, 49.98, 100.0, 399.98))
What I want to do is the sum up all the items in the Iterable[Float] in that RDD’s _2-nd…
Choix
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3 answers
discrepancy in array.reduce javascript
I spent hours trying to debug a particular code, at the very end i noticed something i don't understand with arr reduce function. Take the below code example
var arr = [{
start: 1,
value: 4
}, {
start: 2,
value: 5
}, {
start: 3,
…
Nuru Salihu
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2 answers
Use reduce or map to upper-case every property in a JavaScript object
Is there a way to upper-case all keys of an object using map or reduce so the result may be returned directly?
It works fine with forEach
var o = {
fname: 'john',
lname: 'doe'
}
var result = {}
Object.entries(o)
.forEach((el) => {
…
1252748
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1
vote
4 answers
Concise way to reduce where one of the states throws an exception
I have a bunch of these:
Validation a;
Validation b;
Validation c;
Here are some of their methods:
boolean isValid();
boolean isInvalid(); // === !isValid()
String getError();
Now, I was trying to do…
Andrew Cheong
- 29,362
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1
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2 answers
Behaviour of Scala ReduceLeft
In the following code snippet I'm using reduceLeft and foreach loop to find the sum of the differences of a number against all of the list members. I was expecting that the result from these two would be the same (1050) but reduceLeft is adding…
RAQ
- 119
- 8
1
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1 answer
How does cleanup() method work?
I am currently new to Hadoop. So I have this solved piece of code in MapReduce which finds out the "parts of a country with most 'Data Engineer' jobs for each year" (for example, if the data of the format (Year,Region,Count(Jobs)) is "2016,'XYZ',35"…
Anand Raina
- 17
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1 answer
Sorting array of object inside reduce in JavaScript
I am trying to do sort inside the reduce and I thought I have everything correct but still my result is not sorted as desired.
Here is the code snippet I have:
var studentInfo = [
{
studentId: 1,
addresses: [
{street: '123 Main…
αƞjiβ
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1 answer
transform_reduce with max_element
I am trying to use transform_reduce to transform a set of numbers and then reduce it to the maximum of those elements.
auto lambda = [](uint64_t x) {
return function(x);
};
counting_iterator start(1);
counting_iterator…
Andrew O'Rourke
- 127
- 1
- 9
1
vote
2 answers
Reducing the cyclomatic complexity, multiple if statements java
I have a lot more of these else-if conditions that I have not included. How could I refactor this to reduce the cyclomatic complexity?
if (ONE.equalsIgnoreCase(eachTag.getNodeName()))
{
myclassDto.setOne(formatter
…
user3431624
- 171
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