Scala List concatenation with example

In order to concatenate two lists we need to utilize concat() method in Scala.
Syntax:

List.concat(l1, l2)

In above syntax, l1 is list1 and l2 is list2.
Below is the example to concat two lists in scala.
Example #1:

// Scala program of concat()
// method

// Creating object
object GfG
{

    // Main method
    def main(args:Array[String])
    {

        // Creating two lists
        val m1 = List(1, 2, 3)
        val m2 = List(4, 5, 6)

        // Applying concat method
        val res = List.concat(m1, m2)

        // Displays output
        println(res)

    }
}

Output:

List(1, 2, 3, 4, 5, 6)

Example #2:

// Scala program of concat()
// method

// Creating object
object GfG
{

    // Main method
    def main(args:Array[String])
    {

        // Creating two lists
        val m1 = List(1, 2, 3)
        val m2 = List(3, 4, 5)

        // Applying concat method
        val res = List.concat(m1, m2)

        // Displays output
        println(res)

    }
}

Output:

List(1, 2, 3, 3, 4, 5)

Here, the identical elements are not removed.