In Scala, we can add an element to a hash using the += operator.
Here is an example:
val students = collection.mutable.HashMap[Int, String]() // creating an empty hash with Integer keys and String values
students += (1 -> "John") // adding the first element with key 1 and value "John"
students += (2 -> "Mary") // adding the second element with key 2 and value "Mary"
println(students) // Output: HashMap(1 -> John, 2 -> Mary)
In the above example, we first create an empty HashMap with Int as key and String as value. We then add two elements to the hash using the += operator. The -> operator is used to create a key-value pair, which is then added to the hash. Finally, we print the contents of the hash using the println method.
We can also add multiple elements to the hash at once using the ++= operator. Here is an example:
val students = collection.mutable.HashMap[Int, String]() // creating an empty hash with Integer keys and String values
students ++= Map(1 -> "John", 2 -> "Mary", 3 -> "Bob") // adding three elements to the hash using a Map
println(students) // Output: HashMap(1 -> John, 2 -> Mary, 3 -> Bob)
In this example, we use the ++= operator to add three elements to the hash at once using a Map. The Map contains key-value pairs of type Int and String, which are added to the hash.