7 examples of 'how to prevent duplicate in array push in angular 2' in JavaScript

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function duplicateArray(arr) {
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  var newArr = [];
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  for(var i=0, arrSize=arr.length; i

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

52
function horribleDuplicates (array) {
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    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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    }
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    return false
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}

434
function patchPush (scope, obj, def, key) {
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  var meta = obj[metaKey][key]
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  var branch = def[key]
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  var isMarkerLast = branch[isMarkerLastKey]
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  return function push () {
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    var i = this.length
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    var j = i + arguments.length
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    var marker, currentNode
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    // Passing arguments to apply is fine.
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    var value = Array.prototype.push.apply(this, arguments)
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    for (j = i + arguments.length; i < j; i++) {
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      currentNode = replaceNode(scope, obj, def, key, this[i], null, i)
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      marker = meta.currentMarker
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      if (currentNode)
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        if (isMarkerLast) {
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          marker.parentNode.appendChild(currentNode)
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          marker.parentNode.appendChild(marker)
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        }
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        else marker.parentNode.insertBefore(currentNode, marker)
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      defineIndex(scope, obj, def, key, this, i)
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    }
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    return value
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  }
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}

1
export function isContainsDuplicate2(arr: number[], k: number) {
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  const hash = {}
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  let i = 0
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  while (i < arr.length) {
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    if (i - hash[arr[i]] <= k) return true
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    hash[arr[i]] = i
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    i++
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  }
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  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[] = [];
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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;
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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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}

556
function duplicateArrays(arr, times) {
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  const result = [];
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  for (let i = 0; i <= times; i++) {
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    result.push(...arr.map(a => a.slice(0)));
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  }
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  return result;
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}