String concatenation in Scala

A string is a sequence of characters. In Scala, objects of String are immutable which means a constant and cannot be changed once created. when a new string is created by adding two strings is known as a concatenation of strings. Scala provides concat() method to concatenate two strings, this method returns a new string which is created using two strings. we can also use ‘+’ operator to concatenate two strings. 
Syntax: 
 

str1.concat(str2);

Or

"str1" + "str2";

Below is the example of concatenating two strings.
Using concat() method: This method appends argument to the string.
Example #1: 
 

// Scala program to illustrate how to  
// concatenate strings 
object GFG 
{ 
      
    // str1 and str2 are two strings 
    var str1 = "Welcome! GeeksforGeeks "
    var str2 = " to Portal"
      
    // Main function 
    def main(args: Array[String]) 
    { 
          
        // concatenate str1 and str2 strings 
        // using concat() function 
        var Newstr = str1.concat(str2); 
          
        // Display strings  
        println("String 1:" +str1); 
        println("String 2:" +str2); 
        println("New String :" +Newstr); 
          
        // Concatenate strings using '+' operator 
        println("This is the tutorial" +  
                    " of Scala language" +  
                    " on GFG portal"); 
    } 
} 

Output: 
 

String 1:Welcome! GeeksforGeeks 
String 2: to Portal
New String :Welcome! GeeksforGeeks  to Portal
This is the tutorial of Scala language on GFG portal

In above example, we are joining the second string to the end of the first string by using concat() function. string 1 is Welcome! GeeksforGeeks string 2 is to Portal. After concatenating two string we get new string Welcome! GeeksforGeeks to Portal.
  
Using + operator : we can add two string by using + operator.
Example #2: 
 

// Scala program to illustrate how to 
// concatenate strings 

// Creating object
object GFG 
{
    // Main method
   def main(args: Array[String]) 
   {
        var str1 = "Welcome to ";
        var str2 =  "GeeksforGeeks";
      
        // Concatenating two string
        println("After concatenate two string: " + str1 + str2);
   }
}

Output: 
 

After concatenate two string: Welcome toGeeksforGeeks

In above example, string 1 is Welcome to string 2 is GeeksforGeeks. By using + operator concatenating two string we get output After concatenate two string: Welcome toGeeksforGeeks.