The attribute declaration and naming changes in jsx.
HTML :
<table style="border-collapse : collapse" > </table>
JSX:
<table style={{ borderCollapse : "collapse" }} > </table>
The attribute declaration and naming changes in jsx.
HTML :
<table style="border-collapse : collapse" > </table>
JSX:
<table style={{ borderCollapse : "collapse" }} > </table>
npm run build)./app directory.
arr.reduce((accumulator, currentValue, index, array) => { ... }, initialValue)
collection.Aggregate(
seed,
(acc, current) => ...
)
Optional overload:
collection.Aggregate(
seed,
(acc, current) => ...,
resultSelector
)
stream.reduce(identity, (acc, current) -> ...)
Optional:
stream.reduce((acc, current) -> ...)
---
| Feature | JavaScript | C# | Java |
|---|---|---|---|
| Accumulator | Yes | Yes | Yes |
| Current value | Yes | Yes | Yes |
| Index | Yes | No | No |
| Original array | Yes | No | No |
| Initial value | Optional | Required | Optional |
arr.reduce((acc, x) => acc + x, 0);
arr.Aggregate(0, (acc, x) => acc + x);
Arrays.stream(arr)
.reduce(0, (acc, x) -> acc + x);
---
arr.reduce((acc, x, i, arr) => acc + x / arr.length, 0);
arr.Average();
Manual:
arr.Aggregate(0, (acc, x) => acc + x) / arr.Count();
Arrays.stream(arr).average().getAsDouble();
Manual:
Arrays.stream(arr)
.reduce(0, (acc, x) -> acc + x) / arr.length;
---
arr.reduce((acc, x) => {
acc.sum += x;
acc.count++;
return acc;
}, { sum: 0, count: 0 });
var result = arr.Aggregate(
new { Sum = 0, Count = 0 },
(acc, x) => new { Sum = acc.Sum + x, Count = acc.Count + 1 }
);
var result = Arrays.stream(arr)
.reduce(
new int[]{0,0},
(acc, x) -> new int[]{acc[0] + x, acc[1] + 1},
(a, b) -> new int[]{a[0] + b[0], a[1] + b[1]}
);
---
JavaScript → flexible (extra context available)
C# → structured (LINQ-based aggregation)
Java → functional + parallel-ready reduction
---
JS reduce = flexible loop with extra context
C# Aggregate = structured accumulation
Java reduce = functional + parallel-safe reduction
---
| Language | Nature of Arrays |
|---|---|
| JavaScript | Dynamic, flexible, loosely typed |
| C# | Fixed-size, strongly typed |
| Java | Fixed-size, strongly typed |
Real-world usage:
| Class | Generic Version? |
|---|---|
| ArrayList | No |
| Hashtable | No |
| Stack | No |
| Queue | No |
| Class |
|---|
| List<T> |
| Dictionary<K,V> |
| HashSet<T> |
| Queue<T> |
| Stack<T> |
| LinkedList<T> |
| SortedList<K,V> |
| SortedDictionary<K,V> |
| Category | Examples |
|---|---|
| List | ArrayList, LinkedList |
| Set | HashSet, TreeSet |
| Map | HashMap, TreeMap |
| Queue | PriorityQueue, Deque |
| Concept | JavaScript | C# (LINQ) | Java (Streams) |
|---|---|---|---|
| Transform | map | Select | map |
| Filter | filter | Where | filter |
| Reduce | reduce | Aggregate | reduce |
| FlatMap | flatMap | SelectMany | flatMap |
| Find | find | First | findFirst |
| Any | some | Any | anyMatch |
| All | every | All | allMatch |
| Contains | includes | Contains | contains |
| Sort | sort | OrderBy | sorted |
| Method Type | Returns |
|---|---|
| map/filter/flat | New array |
| reduce | Single value |
| find | Element |
| some/every | Boolean |
| push/unshift | New length |
| pop/shift | Removed element |
| splice | Removed elements (array) |
| sort/reverse | Mutated array |
[1,2,3].map(x => x * 2) → [2,4,6]
[1,2,3].reduce((acc,x) => acc+x,0) → 6
Rule: map = transform, reduce = combine
---arr.reduce((acc,x)=>acc+x,0)
arr.reduce((a,b)=>a+b)
Best practice: Always provide initial value
---[1,[2,3]].flat() → [1,2,3]
[1,2,3].flatMap(x => [x,x*2]) → [1,2,2,4,3,6]
---
arr.Select(...)
arr.Where(...)
arr.Aggregate(...)
arr.SelectMany(...)
stream.map(...)
stream.filter(...)
stream.reduce(...)
stream.flatMap(...)
---
| Concept | Java | C# |
|---|---|---|
| Pattern | Iterator | Enumerator |
| Move | hasNext() | MoveNext() |
| Value | next() | Current |
for loop → fastest
foreach → cleaner
stream → readable but overhead
---
C# Object → JSON/Avro → Kafka → Java Object
---
Arrays → Data
map → Transform
filter → Select
flatMap→ Expand
reduce → Combine
---
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The attribute declaration and naming changes in jsx. HTML : <table style="border-collapse : collapse" > </table> JS...