What is Super keyword in Java A Super keyword in java is a keyword used to access immediate parent class instance variable, methods and constructors. java super keyword used in classes where inheritance hierarchy exists. Uses of super keyword in Java In Java super keyword is used when a sub class wants to refer its … Read more
Java code for inserting data into the database is done using JDBC (Java Database connectivity). JDBC is an API to connect the java programs to various databases like MySql, Oracle, MSAccess, etc. Here Step by step tutorial to insert data from java into the database. Here MySql or MariaDB database is used for this purpose. … Read more
The number which is divisible by 2 is known as even number and the number which is not divisible by 2 is odd number. in programming we use % operator to check divisibility. The % operator returns the remainder of division. If a number is completely divisible its remainder is 0. So any number is … Read more
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | public class StringSplit { public static void main(String[] s) { String sentence = "The Java language was designed at Sun Microsystems over a five year " +"period, culminating in its first release in January 1996"; StringSplit st = new StringSplit(); st.split(sentence); } public void split(String sentence) { String[] words = sentence.split(" "); System.out.println("Words are:"); for(String word: words) { System.out.println(word); } } } |
In Java, you can reverse a string in several ways. Here are three common methods to reverse a string: String reverse program in java using StringBuilder
1 2 3 4 5 6 7 8 | public class StringReverseExample { public static void main(String[] args) { String original = "Hello, World!"; StringBuilder reversed = new StringBuilder(original).reverse(); String reversedString = reversed.toString(); System.out.println("Reversed string: " + reversedString); } } |
This program uses the StringBuilder class, which is a mutable sequence of characters. Here’s how it works: Using a loop to reverse the string character by character:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | public class StringReverseExample { public static void main(String[] args) { String original = "Hello, World!"; String reversed = reverseString(original); System.out.println("Reversed string: " + reversed); } public static String reverseString(String str) { StringBuilder reversed = new StringBuilder(); for (int i = str.length() - 1; i >= 0; i--) { reversed.append(str.charAt(i)); } return reversed.toString(); } } |
suspend() : This method suspend a thread for sometime but do not kill/terminate it. resume() : This method revives the suspended thread.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | class A extends Thread { public void run() { for (int i = 1; i <= 5; i++) { System.out.println("A" + i); } System.out.println("Exit from A"); } } class B extends Thread { public void run() { for (int i = 1; i <= 5; i++) { System.out.println("B" + i); } System.out.println("Exit from B"); } } public class TestMain { public static void main(String args[]) { A a = new A(); B b = new B(); a.start(); b.start(); a.suspend(); a.resume(); } } |
1 2 3 4 5 6 7 8 9 10 11 12 | A1 A2 A3 A4 A5 Exit from A B1 B2 B3 B4 B5 Exit from B |
To run applets we use appletviewer . An appletviewer is command line program to invoke an applet program from command line. Here we will see how to run applet from applet viewer Example : Write a simple applet program to print “ Hello Students”
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | import java.applet.Applet; import java.awt.Graphics; /* <applet code="APdemo.class" width="300" height="300"> </applet> */ public class APdemo extends Applet { String s = "Hello Students"; public void paint(Graphics g) { g.drawString(s, 100, 100); // print string at 100*100 pixel location } } |
Compile Save & Run: Save this file with APDemo.java name. Compile : … Read more
String reversal is changing the characters position from last to first in string. There are different ways to to achieve reversal. We will see them one by one. Using Loops (or Iterations) Usnig StringBuffer or StringBuilder ‘s reverse() Using toCharArray() of Array Using Recursion Using Collections Lets see different ways one by one 1 Reverse … Read more
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | import java.util.StringTokenizer; public class StringCount { public static void main(String[] s) { String sentence = "The Java language was designed at Sun Microsystems over a five year " + "period, culminating in its first release in January 1996"; StringCount st = new StringCount(); st.count(sentence); st.countByTokenizer(sentence); } public void count(String sentence) { String[] words = sentence.split(" "); System.out.println("Number of characters " + sentence.length()); System.out.println("Number of words " + words.length); } public void countByTokenizer(String sentence) { StringTokenizer st = new StringTokenizer(sentence); System.out.println("Number of characters " + sentence.length()); System.out.println("Number of words " + st.countTokens()); } } |
We can replace a sub string using replaceAll() of String class To show this take one example: Consider We want to change a string result count value given like 1,420,000 we would like to change it to long value we directly convert it to long it will throw java.lang.NumberFormatException. To convert given string value to … Read more
