I have an array of numbers that I need to make sure are unique. I found the code snippet below on the Internet, and it works great until the array has a zero in it. I found this other script here on Stack Overflow that looks almost exactly like it, but it doesn't fail.
How can I determine where the prototype script is going wrong?
Array.prototype.getUnique = function() {
var o = {}, a = [], i, e;
for (i = 0; e = this[i]; i++) {o[e] = 1};
for (e in o) {a.push (e)};
return a;
}
Short and sweet prototype solution:
Array.prototype.unique = function() {
return [...new Set(this)]
}
let arr = [1,5,1,2,2,1,3,2,3,3,3,1,10]
for(let i = 0; i<arr.length; i++) {
for(let j = i+1; j<arr.length;j++) {
if(arr[i] === arr[j]) {
arr[j] = 0;
}
}
if(arr[i] === 0) {
arr.splice(i,1)
i--
}
}
console.log(arr)
(function() {
"use strict";
Array.prototype.unique = function unique() {
var self = this;
return self.filter(function(a) {
var that = this;
// console.log(that);
return !that[a] ? that[a] = true : false;
}, {});
}
var sampleArray = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
var distinctArray = sampleArray.unique();
console.log(distinctArray);
})();Here is the simple way to solve this problem...I would sort the array, then all duplicates are neighbours. Then walk once through the array and eliminate all duplicates.
function getUniques(array) {
var l = array.length
if(l > 1) {
// get a cloned copy and sort it
array = [...array].sort();
var i = 1, j = 0;
while(i < l) {
if(array[i] != array[j]) {
array[++j] = array[i];
}
i++;
}
array.length = j + 1;
}
return array;
}
