7 examples of 'count duplicate elements in array javascript' in JavaScript

64
function duplicateArray(array) {
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  return array.clone ? array.clone() : new Array(array.length);
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}

30
function duplicateArray(arr) {
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  var newArr = [];
32
  for(var i=0, arrSize=arr.length; i<arrSize; i++) {
33
    newArr.push(arr[i]);
34
  }
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  return newArr;
36
}

1
function countDuplicateArgs() {
2
  const memo = {};
3
  let areDuplicates = false;
4
  Object.values(arguments).forEach((n) => {
5
    if (!(n in memo)) memo[n] = 1;
6
    else areDuplicates = true;
7
  });
8
  return areDuplicates;
9
}

70
function getCountOfDuplicates(changes: Change[]): CountOfDuplicateChanges {
71
  return ArrayUtils.countDuplicates(
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    changes,
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    change => [change.type, change.action, change.name]
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  ) as CountOfDuplicateChanges;
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}

1
function count_same_elements(collection) {
2
  return collection
3
}

52
function horribleDuplicates (array) {
53
    for (var i = 0; i < array.length; i++) {
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        for (var j = 0; j < array.length; j++) {
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            if (array[i] == array[j]) {
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                return true
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            }
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        }
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    }
60
    return false
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}

270
export function getDuplicateNames(indexableArray: { name: string }[]): string[] {
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  const seen: { [name: string]: number } = {};
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  const duplicates: string[] = [];
273
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  indexableArray.forEach((element: { name: string }) => {
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    const { name } = element;
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    const count = seen[name] || 0;
277
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    if (count === 1) {
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      duplicates.push(name);
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    }
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    seen[name] = count + 1;
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  });
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  return duplicates;
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}