JavaScript: How to Remove Duplicate Values from a Array?

  Use the indexOf() method in conjugation with the push() remove the duplicate values from an array or get all unique values from an array in JavaScript.

For ex:

<script>
  // Defining function to get unique values from an array
  function getUnique(array)
{
    var uniqueArray = [];
    // Loop through array values
    for(i=0; i < array.length; i++)
{
      if(uniqueArray.indexOf(array[i]) === -1) {
        uniqueArray.push(array[i]);
      }
    }
    return uniqueArray;
  }
  var names = ["John", "Peter", "Clark", "Harry", "John", "Alice"];
  var uniqueNames = getUnique(names);
  console.log(uniqueNames); // Prints: ["John", "Peter", "Clark", "Harry", "Alice"]
</script>

or

  Use the for-of loop instead of for loop to perform this filtration very easily,like this:

<script>
  // Defining function to get unique values from an array
  function getUnique(array)
{
    var uniqueArray = [];
    // Loop through array values
    for(var value of array)
{
      if(uniqueArray.indexOf(value) === -1)
{
        uniqueArray.push(value);
      }
    }
    return uniqueArray;
  }
  var names = ["John", "Peter", "Clark", "Harry", "John", "Alice"];
  var uniqueNames = getUnique(names);
  console.log(uniqueNames); // Prints: ["John", "Peter", "Clark", "Harry", "Alice"]
</script>