JAVA Question : Programming Assignment
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The document provides several Java programming exercises, including reversing a string without using built-in functions, swapping two numbers with and without a third variable, and counting the number of words in a string using a HashMap. Each exercise is accompanied by example code illustrating the implementation. The code snippets demonstrate fundamental programming concepts and techniques in Java.
![1) Write a Java Program to reverse a string without
using String inbuilt function.
Following program code explains this:
public class FinalReverseWithoutUsingStringMethods {
public static void main(String[] args) {
// TODO Auto-generated method stub
String str = "Automation";
StringBuilder str2 = new StringBuilder();
str2.append(str);
str2 = str2.reverse(); // used string builder to reverse
System.out.println(str2);
}
}](https://image.slidesharecdn.com/codingassignmenthelp-230626110127-d51191e8/85/JAVA-Question-Programming-Assignment-2-320.jpg)
![2) Write a Java Program to reverse a string without using
String inbuilt function reverse()
Answer: There are several ways with which you can reverse your string if you are allowed to use the
other string inbuilt functions.
In this method, we are initializing a string variable called str with the value of your given string. Then,
we are converting that string into a character array with the toCharArray() function. Thereafter, we are
using for loop to iterate between each character in reverse order and printing each character.
public class FinalReverseWithoutUsingInbuiltFunction {
public static void main(String[] args) {
String str = "Saket Saurav";
char chars[] = str.toCharArray(); // converted to character array and printed in reverse order
for(int i= chars.length-1; i>=0; i--) {
System.out.print(chars[i]);
}
}
}](https://image.slidesharecdn.com/codingassignmenthelp-230626110127-d51191e8/85/JAVA-Question-Programming-Assignment-3-320.jpg)
![3) Write a Java Program to swap two numbers using the
third variable.
import java.util.Scanner;
public class SwapTwoNumbers {
public static void main(String[] args) {
// TODO Auto-generated method stub
int x, y, temp;
System.out.println("Enter x and y");
Scanner in = new Scanner(System.in);
x = in.nextInt();
y = in.nextInt();
System.out.println("Before Swapping" + x + y);
temp = x;
x = y;
y = temp;
System.out.println("After Swapping" + x + y);
}
}](https://image.slidesharecdn.com/codingassignmenthelp-230626110127-d51191e8/85/JAVA-Question-Programming-Assignment-4-320.jpg)
![4) Write a Java Program to swap two numbers without using
the third variable.
import java.util.Scanner;
class SwapTwoNumberWithoutThirdVariable
{
public static void main(String args[])
{
int x, y;
System.out.println("Enter x and y");
Scanner in = new Scanner(System.in);
x = in.nextInt();
y = in.nextInt();
System.out.println("Before Swappingnx = "+x+"ny = "+y);
x = x + y;
y = x - y;
x = x - y;
System.out.println("After Swapping without third variablenx = "+x+"ny = "+y);
}
}](https://image.slidesharecdn.com/codingassignmenthelp-230626110127-d51191e8/85/JAVA-Question-Programming-Assignment-5-320.jpg)
![5) Write a Java Program to count the number of words in a
string using HashMap.
import java.util.HashMap;
public class FinalCountWords {
public static void main(String[] args) {
// TODO Auto-generated method stub
String str = "This this is is done by Saket Saket";
String[] split = str.split(" ");
HashMap<String,Integer> map = new HashMap<String,Integer>();
for (int i=0; i<split.length; i++) {
if (map.containsKey(split[i])) {
int count = map.get(split[i]);
map.put(split[i], count+1);
}
else {
map.put(split[i], 1);
}
}
System.out.println(map);
}
}](https://image.slidesharecdn.com/codingassignmenthelp-230626110127-d51191e8/85/JAVA-Question-Programming-Assignment-6-320.jpg)
JAVA Question : Programming Assignment
- 2. 1) Write a Java Program to reverse a string without using String inbuilt function. Following program code explains this: public class FinalReverseWithoutUsingStringMethods { public static void main(String[] args) { // TODO Auto-generated method stub String str = "Automation"; StringBuilder str2 = new StringBuilder(); str2.append(str); str2 = str2.reverse(); // used string builder to reverse System.out.println(str2); } }
- 3. 2) Write a Java Program to reverse a string without using String inbuilt function reverse() Answer: There are several ways with which you can reverse your string if you are allowed to use the other string inbuilt functions. In this method, we are initializing a string variable called str with the value of your given string. Then, we are converting that string into a character array with the toCharArray() function. Thereafter, we are using for loop to iterate between each character in reverse order and printing each character. public class FinalReverseWithoutUsingInbuiltFunction { public static void main(String[] args) { String str = "Saket Saurav"; char chars[] = str.toCharArray(); // converted to character array and printed in reverse order for(int i= chars.length-1; i>=0; i--) { System.out.print(chars[i]); } } }
- 4. 3) Write a Java Program to swap two numbers using the third variable. import java.util.Scanner; public class SwapTwoNumbers { public static void main(String[] args) { // TODO Auto-generated method stub int x, y, temp; System.out.println("Enter x and y"); Scanner in = new Scanner(System.in); x = in.nextInt(); y = in.nextInt(); System.out.println("Before Swapping" + x + y); temp = x; x = y; y = temp; System.out.println("After Swapping" + x + y); } }
- 5. 4) Write a Java Program to swap two numbers without using the third variable. import java.util.Scanner; class SwapTwoNumberWithoutThirdVariable { public static void main(String args[]) { int x, y; System.out.println("Enter x and y"); Scanner in = new Scanner(System.in); x = in.nextInt(); y = in.nextInt(); System.out.println("Before Swappingnx = "+x+"ny = "+y); x = x + y; y = x - y; x = x - y; System.out.println("After Swapping without third variablenx = "+x+"ny = "+y); } }
- 6. 5) Write a Java Program to count the number of words in a string using HashMap. import java.util.HashMap; public class FinalCountWords { public static void main(String[] args) { // TODO Auto-generated method stub String str = "This this is is done by Saket Saket"; String[] split = str.split(" "); HashMap<String,Integer> map = new HashMap<String,Integer>(); for (int i=0; i<split.length; i++) { if (map.containsKey(split[i])) { int count = map.get(split[i]); map.put(split[i], count+1); } else { map.put(split[i], 1); } } System.out.println(map); } }