Which of the following returns a String?

1. length()
2. charAt(int)
3. replace(char, char)
4. indexOf(String)

Consider the following program segment in which the statements are jumbled, choose the correct order of statements to check if a given word is Palindrome or not.

boolean palin(String w) {
    boolean isPalin;
    w = w.toUpperCase();
    int l = w.length();
    isPalin = false; // Stmt (1)
    for (int i = 0; i < l / 2; i++) {
        char c1 = w.charAt(i),
                c2 = w.charAt(l - 1 - i); // Stmt (2)
        if (c1 != c2) {
            break; // Stmt (3)
            isPalin = true; // Stmt (4)
        }
    }
    return isPalin;
}

Write a program in Java to enter any sentence. Also ask the user to enter a word. Print the number of times the word entered is present in the sentence. If the word is not present in the sentence, then print an appropriate message.

A university student's registration number follows the format:

<CourseCode><Year><CollegeCode><RollNumber>

where

Component	Description
CourseCode	A 3-letter code representing the course (e.g., CSE for Computer Science, ECE for Electronics & Communication)
Year	The last two digits of the admission year.
CollegeCode	A 3-digit code representing the college
RollNumber	A 4-digit unique student roll number.

Examples

Registration Number	Course Code	Admission Year	College Code	Roll Number
CSE240011023	CSE	24	001	1023
ECE252104297	ECE	25	210	4297
ASE230277259	ASE	23	027	7259

Define a class that accepts a student's registration number as input, extracts the relevant details, and displays them in the specified format.

import java.util.Scanner;

public class KboatStuRegNum
{
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter reg. no.: ");
        _______(1)_________
        
        int l = n.length();
        if (l != 12) {
            System.out.println("Invalid reg. no.");
            System.exit(0);
        }   
        
        _______(2)_________
        _______(3)_________
        _______(4)_________
        _______(5)_________
        
        System.out.println("Course Code    : " + cc);
        System.out.println("Admission Year : " + yr);
        System.out.println("College Code   : " + cl);
        System.out.println("Roll Number    : " + rNo);
    }
}