Multiple methods of array de-weight implementation

<script>

The first way
var arr=[23,1,34,7,1,3,5,2,3]; Define an array
var newArr = []; To define a new temporary array
var result = {}; Hash table
for (Var i=0;i<arr.length;i++) {//Iterate through an array
if (!result[arr[i]]) {//If the traversed array is not in the hash table
Result[arr[i]] = true; Deposits the currently traversed array element into the hash table
Newarr.push (Arr[i]); Push the current element to a new array
}
}
Console.log (NEWARR);

The second method of
var arr=[23,1,34,7,1,3,5,2,3]; Define an array
var newArr = []; To define a new temporary array
for (Var i=0;i<arr.length;i++) {//traversal array
if (Newarr.indexof (Arr[i]) ==-1) Newarr.push (Arr[i]);
Determines whether the current element can be found in a temporary array, appends it to a temporary array if it is not found, and then continues to find and compare elements behind the current element
}

Console.log (NEWARR);

The Third Way
var arr=[23,1,34,7,1,3,5,2,3]; Define an array
Arr.sort (); Sort the array first
var newarr=[arr[0]]; Defines a new array and places the first element of the array in a new array
for (Var i=0;i<arr.length;i++) {
if (Arr[i]!==newarr[newarr.length-1]) {//By judging whether two adjacent items are equal, then appending elements to the new array, returning the new array
Newarr.push (Arr[i]);
}
}
Console.log (NEWARR);

</script>

Multiple methods for array de-weight implementation