extract array duplicates js code example
Example 1: javascript get duplicates in array
function getDuplicateArrayElements(arr){
var sorted_arr = arr.slice().sort();
var results = [];
for (var i = 0; i < sorted_arr.length - 1; i++) {
if (sorted_arr[i + 1] === sorted_arr[i]) {
results.push(sorted_arr[i]);
}
}
return results;
}
var colors = ["red","orange","blue","green","red","blue"];
var duplicateColors= getDuplicateArrayElements(colors);
Example 2: function that duplicates data in array js
function doubleValues(array) {
var newArray = [];
array.forEach(function (el) { newArray.push(el, el); });
return newArray;
}
console.log(doubleValues([1,2,3]));