How to Get Unique Values from Array

Get all unique values in a JavaScript array (remove duplicates)

With JavaScript 1.6 / ECMAScript 5 you can use the native filter method of an Array in the following way to get an array with unique values:

function onlyUnique(value, index, self) {
  return self.indexOf(value) === index;
}

// usage example:
var a = ['a', 1, 'a', 2, '1'];
var unique = a.filter(onlyUnique);

console.log(unique); // ['a', 1, 2, '1']

How to get unique values in an array

Since I went on about it in the comments for @Rocket's answer, I may as well provide an example that uses no libraries. This requires two new prototype functions, contains and unique

Array.prototype.contains = function(v) {  for (var i = 0; i < this.length; i++) {    if (this[i] === v) return true;  }  return false;};
Array.prototype.unique = function() {  var arr = [];  for (var i = 0; i < this.length; i++) {    if (!arr.contains(this[i])) {      arr.push(this[i]);    }  }  return arr;}
var duplicates = [1, 3, 4, 2, 1, 2, 3, 8];var uniques = duplicates.unique(); // result = [1,3,4,2,8]
console.log(uniques);

Get unique values from array of arrays

You can use .flat() to flatten your array and then use Set to get its unique values.

Demo:

let arr =   [  [    "s1@example.com",    "s2@example.com"  ],  [    "s1@example.com",    "s3@example.com"  ]]
let arr2 = [...new Set(arr.flat(1))];console.log(arr2)

How to get distinct values from an array of objects in JavaScript?

If this were PHP I'd build an array with the keys and take array_keys at the end, but JS has no such luxury. Instead, try this:

var flags = [], output = [], l = array.length, i;
for( i=0; i<l; i++) {
    if( flags[array[i].age]) continue;
    flags[array[i].age] = true;
    output.push(array[i].age);
}

Filter array to have unique values

You can use Array.filter function to filter out elements of an array based on the return value of a callback function. The callback function runs for every element of the original array.

The logic for the callback function here is that if the indexOf value for current item is same as the index, it means the element has been encountered first time, so it can be considered unique. If not, it means the element has been encountered already, so should be discarded now.

var arr = ["X_row7", "X_row4", "X_row6", "X_row10", "X_row8", "X_row9", "X_row11", "X_row7", "X_row4", "X_row6", "X_row10", "X_row8", "X_row9", "X_row11", "X_row7", "X_row4", "X_row6", "X_row10", "X_row8", "X_row9", "X_row11", "X_row7", "X_row4", "X_row6", "X_row10", "X_row8", "X_row9", "X_row11", "X_row7", "X_row4", "X_row6", "X_row10", "X_row8", "X_row9", "X_row11", "X_row7", "X_row4", "X_row6", "X_row10", "X_row8", "X_row9", "X_row11"];
var filteredArray = arr.filter(function(item, pos){  return arr.indexOf(item)== pos; });
console.log( filteredArray );

Getting unique values from an Array for use in ListItem

Edit I misunderstood the question, I would suggest using reduce.

note I made all require statements a string for this example to run

const Users = [{
    id: 1,
    name: "user1",
    image: 'require("../assets/1.jpeg")',
    location: "Portland"
  },
  {
    id: 2,
    name: "user2",
    image: 'require("../assets/2.jpeg")',
    location: "Portland"
  },
  {
    id: 3,
    name: "user3",
    image: 'require("../assets/3.jpeg")',
    location: "New York"
  },
  {
    id: 4,
    name: "user4",
    image: 'require("../assets/4.jpeg")',
    location: "Pullman"
  },
  {
    id: 5,
    name: "user5",
    image: 'require("../assets/5.jpeg")',
    location: "Portland"
  },
  {
    id: 6,
    name: "user6",
    image: 'require("../assets/6.jpeg")',
    location: "San Francisco"
  },
  {
    id: 7,
    name: "user7",
    image: 'require("../assets/7.jpeg")',
    location: "Pullman"
  },
];

console.log(Users.reduce((acc, val) => {
  acc[val.location] = acc[val.location] ? [...acc[val.location], val] : [val];
  return acc
}, {}))

vba: get unique values from array

This post contains 2 examples. I like the 2nd one:

Sub unique() 
  Dim arr As New Collection, a 
  Dim aFirstArray() As Variant 
  Dim i As Long 
 
  aFirstArray() = Array("Banana", "Apple", "Orange", "Tomato", "Apple", _ 
  "Lemon", "Lime", "Lime", "Apple") 
 
  On Error Resume Next 
  For Each a In aFirstArray 
     arr.Add a, a 
  Next
  On Error Goto 0 ' added to original example by PEH
 
  For i = 1 To arr.Count 
     Cells(i, 1) = arr(i) 
  Next 
 
End Sub 

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