<script>
var arr = [1, 1, 2, 3, 4, 4, 2, 1, 3, 5]
for (i = 0; i < arr.length - 1; i++) {
for (j = i + 1; j < arr.length; j++) {
if (arr[i] == arr[j]) {
arr.splice(j, 1)
}
}
} console.log(arr)
</script>
<script>
var arr = [1, 1, 2, 3, 4, 4, 2, 1, 3, 5]
for (i = 0; i < arr.length - 1; i++) {
for (j = i + 1; j < arr.length; j++) {
if (arr[i] == arr[j]) {
arr.splice(j, 1)
}
}
} console.log(arr)
</script>