Answer:
Here is the corrected program:
import java.util.Scanner; //to accept input from user
public class 02_14_Activity_one { //class name
public static void main(String[] args) { //start of main method
Scanner scan = new Scanner(System.in); //creates Scanner class object
System.out.println("Enter first string"); //prompts user to enter first string
String s1 = scan.nextLine(); //reads input string from user
System.out.println("Enter second string"); //prompts user to enter second string
String s2 = scan.nextLine(); //reads second input string from user
System.out.println("Enter number of letters from each word"); //enter n
int n = scan.nextInt(); //reads value of integer n from user
System.out.println(s1.substring(0,n) + s2.substring(s2.length() - n ));
} } //uses substring method to print a string made up of the first n letters of s1 and the last n letters of s2.
Explanation:
The errors were:
1.
Scanner scan = Scanner(System.in);
Here new keyword is missing to create object scan of Scanner class.
Corrected statement:
Scanner scan = new Scanner(System.in);
2.
String s1 = nextLine();
Here object scan is missing to call nextLine() method of class Scanner
Corrected statement:
String s1 = scan.nextLine();
3.
String s2 = Scanner.nextLine();
Here class is used instead of its object scan to access the method nextLine
Corrected statement:
String s2 = scan.nextLine();
4.
String n = scan.nextLine();
Here n is of type String but n is a whole number so it should be of type int. Also the method nextInt will be used to scan and accept an integer value
Corrected statement:
int n = scan.nextInt();
5.
System.out.println(s1.substring(1,n-1) + s2.substring(s1.length()-n));
This statement is also not correct
Corrected statement:
System.out.println(s1.substring(0,n) + s2.substring(s2.length() - n ));
This works as follows:
s1.substring(0,n) uses substring method to return a new string that is a substring of this s1. The substring begins at the 0th index of s1 and extends to the character at index n.
s2.substring(s2.length() - n ) uses substring method to return a new string that is a substring of this s2. The substring then uses length() method to get the length of s2 and subtracts integer n from it and thus returns the last n characters of s2.
The screenshot of program along with its output is attached.