Scala Programming: Create a new string taking the first 3 characters of a given string and return the string with the 3 characters added at both the front and back

Scala Programming Basic Exercise-12 with Solution

Write a Scala program to create a new string taking the first 3 characters of a given string and return the string with the 3 characters added at both the front and back. If the given string length is less than 3, use whatever characters are there.

Sample Solution:

Scala Code:

// Define an object named scala_basic
object scala_basic {
  // Define a function named test with parameter str1 of type String, returning a String
  def test(str1: String): String =
    {
      // Check if the length of the input string is less than 3
      if (str1.length < 3)
        // If true, repeat the string three times using the * operator
        str1 * 3
      else
        // If false, concatenate the substring of the first three characters, the input string, and the substring of the first three characters
        str1.substring(0, 3) + str1 + str1.substring(0, 3)
    }

   // Define the main method, which is the entry point of the program
   def main(args: Array[String]): Unit = {
      // Print the result of calling test with the argument "Scala"
      println("Result: " + test("Scala"))
      
      // Print the result of calling test with the argument "abcd"
      println("Result: " + test("abcd"))
      
      // Print the result of calling test with the argument "ab"
      println("Result: " + test("ab"))
      
      // Print the result of calling test with the argument "a"
      println("Result: " + test("a"))
    }
}

Sample Output:

Result: ScaScalaSca
Result: abcabcdabc
Result: ababab
Result: aaa

Explanation:

Here is the break down of the said Scala code:

• object scala_basic {: This declares an object named scala_basic.
• def test(str1: String): String =: This line defines a function named test that takes a parameter str1 of type String and returns a String. The function checks if the length of the input string is less than 3. If true, it repeats the string three times using the * operator. If false, it concatenates the substring of the first three characters, the input string, and the substring of the first three characters.
• if (str1.length < 3) str1 3: This is a conditional expression inside the "test()" function. If the length of the string str1 is less than 3, it returns the string repeated three times using the operator.
• else str1.substring(0, 3) + str1 + str1.substring(0, 3): If the length of the string is 3 or more, it concatenates the substring of the first three characters, the input string, and the substring of the first three characters.
• def main(args: Array[String]): Unit = {: This line defines the main method, which is the entry point of the program. It takes an array of strings (args) as its parameter and returns Unit (similar to void in other languages).
• println("Result: " + test("Scala")): This line calls the "test()" function with the argument "Scala", concatenates the result with the string "Result: ", and prints the entire string to the console.
• println("Result: " + test("abcd")): Similar to the previous line, this calls the "test()" function with the argument "abcd".
• println("Result: " + test("ab")): Another call to the "test()" function with the argument "ab".
• println("Result: " + test("a")): Another call to the "test()" function with the argument "a".

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