ManaliDubal

// Convert uppercase to lowercase and vice-versa. 
import java.util.Scanner;
class test {
public static void main(String ar[]) {
  
	Scanner sc=new Scanner(System.in);
	System.out.println("Enter any string:");
	String name = sc.nextLine();
	String ans="";
	// extract each character from user_id by charAt() method.

ManaliDubal

// Using isUpperCase() to check whether name or any string entered by user is uppercase  or not. 
import java.util.Scanner;
class test
{
public static void main(String ar[])
{
	Scanner sc=new Scanner(System.in);
	System.out.println("Enter any string:");
	String name = sc.nextLine();
	// extract each character from name by charAt() method.

ManaliDubal

// Using isLowerCase() to check whether name or any string entered by user is lowercase. 
import java.util.Scanner;
class test {
public static void main(String ar[]) {

	Scanner sc=new Scanner(System.in);
	System.out.println("Enter any string:");
	String name = sc.nextLine();
	// extract each character from user_id by charAt() method.
	for(int i=0;i<name.length();i++)

ManaliDubal

// Using isLetterOrDigit() to check whether user_id or any string entered by user has a digit and/or letter and no other symbols or characters. 
import java.util.Scanner;
class test {
public static void main(String ar[]) {
	Scanner sc=new Scanner(System.in);
	boolean flag =false; // keep the switch/flag off in the beginning. 
	System.out.println("Enter user_id:");
	String user_id = sc.nextLine();
	// extract each character from user_id by charAt() method.
	for(int i=0;i<user_id.length();i++)

ManaliDubal

// Using isLetter() to check whether contact number or any integer input entered by user has a letter or not.
import java.util.Scanner;
class test {
public static void main(String ar[]) {
  Scanner sc=new Scanner(System.in);
	boolean flag =false; // keep the switch/flag off in the beginning. 
	System.out.println("Enter phone number:");
	String number = sc.nextLine();
	if(number.length()==10){
	// extract each character from number by charAt() method.

ManaliDubal

// Using isDigit() to check whether name or any string entered by user has a digit or not.
import java.util.Scanner;
class test {
public static void main(String ar[]) {
	Scanner sc=new Scanner(System.in);
	boolean flag =false; // keep the switch/flag off in the beginning. 
	System.out.println("Enter name:");
	String name = sc.nextLine();
	// extract each character from name by charAt() method.
	for(int i=0;i<name.length();i++)

ManaliDubal

// Print the ASCII values for all the characters present in the input string entered by user
import java.util.Scanner;
class test {
public static void main(String ar[]) {     
	Scanner scan = new Scanner(System.in);
	System.out.println("Enter the string:");
	String str = scan.next();// input a string. 
	// As string is combination of different characters, we need to extrac 
	// individual character and then print the ASCII respectivly. 
	for(int i=0;i<str.length();i++)

ManaliDubal

// ASCII code demo
import java.util.Scanner;
class test {
public static void main(String ar[]) {     
	Scanner scan = new Scanner(System.in);
	System.out.println("Enter the integer ASCII code:");
	int value = scan.nextInt(); // input of Decimal value 
	// Just covert the integer to character.
	char ch = (char)value; 
	System.out.println("Character value for ASCII code: "+value+" is "+ch );

ManaliDubal

// ASCII code demo
import java.util.Scanner;
class test {
public static void main(String ar[]) {     
	Scanner scan = new Scanner(System.in);
	System.out.println("Enter the character to check the ASCII code:");
	char ch = scan.next().charAt(0); // input of character
	// We know that the (Decimal) integer value of a character is its ASCII value. 
	// Hence, just coverting the character to integer will do the triick.
	int value = (int)ch; 

ManaliDubal

// Linear Search in Java -> for integers
import java.util.Scanner;
class test
{
public static void main(String ar[])
{     
	Scanner scan = new Scanner(System.in);
	System.out.println("Enter the size of array:");
	int size = scan.nextInt();
	scan.nextLine(); //clear the buffer after integer input.