“Znajdź duplikaty w tablicy” Kod odpowiedzi

Znajdź zduplikowane wartości w tablicy JavaScript

const findDuplicates = (arr) => {
  let sorted_arr = arr.slice().sort(); // You can define the comparing function here. 
  // JS by default uses a crappy string compare.
  // (we use slice to clone the array so the
  // original array won't be modified)
  let results = [];
  for (let i = 0; i < sorted_arr.length - 1; i++) {
    if (sorted_arr[i + 1] == sorted_arr[i]) {
      results.push(sorted_arr[i]);
    }
  }
  return results;
}

let duplicatedArray = [9, 4, 111, 2, 3, 4, 9, 5, 7];
console.log(`The duplicates in ${duplicatedArray} are ${findDuplicates(duplicatedArray)}`);
Fancy Fish

JS Znajdź duplikaty w tablicy

const names = ['Mike', 'Matt', 'Nancy', 'Adam', 'Jenny', 'Nancy', 'Carl']

const count = names =>
  names.reduce((a, b) => ({ ...a,
    [b]: (a[b] || 0) + 1
  }), {}) // don't forget to initialize the accumulator

const duplicates = dict =>
  Object.keys(dict).filter((a) => dict[a] > 1)

console.log(count(names)) // { Mike: 1, Matt: 1, Nancy: 2, Adam: 1, Jenny: 1, Carl: 1 }
console.log(duplicates(count(names))) // [ 'Nancy' ]
Restu Wahyu Saputra

Znajdź duplikaty w tablicy

function findDuplicates(arr) {
	const duplicates = new Set()
  
  return arr.filter(item => {
  	if (duplicates.has(item)) {
    	return true
    }
    duplicates.add(item)
    return false
  })
}
Raserad

Znajdź zduplikowane wartości w tablicy JavaScript

const findDuplicates = (arr) => {
  let sorted_arr = arr.slice().sort(); // You can define the comparing function here. 
  // JS by default uses a crappy string compare.
  // (we use slice to clone the array so the
  // original array won't be modified)
  let results = [];
  for (let i = 0; i < sorted_arr.length - 1; i++) {
    if (sorted_arr[i + 1] == sorted_arr[i]) {
      results.push(sorted_arr[i]);
    }
  }
  return results;
}

let duplicatedArray = [9, 4, 111, 2, 3, 9, 4, 5, 7];
console.log(`The duplicates in ${duplicatedArray} are ${findDuplicates(duplicatedArray)}`);
Fancy Fish

Znajdź duplikat elementu na tablicy

const order = ["apple", "banana", "orange", "banana", "apple", "banana"];

const result = order.reduce(function (prevVal, item) {
    if (!prevVal[item]) {
        // if an object doesn't have a key yet, it means it wasn't repeated before
        prevVal[item] = 1;
    } else {
        // increase the number of repetitions by 1
        prevVal[item] += 1;
    }

    // and return the changed object
    return prevVal;
}, {}); // The initial value is an empty object.

console.log(result); // { apple: 2, banana: 3, orange: 1 }
Cruel Cormorant

Znajdź duplikatów JavaScript

let arr = [1, 7, 8, 9, 10, 20, 33, 0, 20, 7, 1]
console.log([... new Set(arr)]
// Output : [1, 7, 8, 9, 10, 20, 33, 0]
Wide-eyed Wolf

Odpowiedzi podobne do “Znajdź duplikaty w tablicy”

Pytania podobne do “Znajdź duplikaty w tablicy”

Więcej pokrewnych odpowiedzi na “Znajdź duplikaty w tablicy” w JavaScript

Przeglądaj popularne odpowiedzi na kod według języka

Przeglądaj inne języki kodu

Shell/Bash
C#
C++
C
CSS
HTML
Java
JavaScript
Objective-C
PHP
Python
Sql
Swift
Ruby
TypeScript
Go
Kotlin
Assembly
R
VBA
Scala
Rust
Dart
Elixir
Clojure
Haskell
Matlab
Erlang
Cobol
Fortran
Scheme
Perl
Groovy
Lua
Julia
Delphi
Abap
Lisp
Prolog
Pascal
ActionScript
Basic
Solidity
PowerShell
GDScript
Excel