In java, a basic input-output stream provides a method for reading & writing bytes or characters in a file. If we want to read-write primitive data types (such as int, float, etc.) then we can use filter classes to filter data in the original stream. DataInputStream & DataOutputStream are two filter classes used for creating … Read more
A Leap Year is a year which has 366 days. This year February is of 29 days. Leap years occurs in every four years. A leap year has following constraints. We can check in programming as below A year is divisible by 400 then it is a leap year A year is divisible by 4 … Read more
Pi (π) is a well-known mathematical constant whose value is 22/7 or 3.14159265359. Programming languages also use this constant for mathematical calculation. Here we discuss PI with respect to the Java programming language. In Java PI is defined as a field in java.lang.Math class. It is defined as static double PI and described as The double value … Read more
To convert java.util.Date to java.sql.TimeStamp as given below
1 2 | Date date=new Date(); Timestamp timestamp = new Timestamp(date.getTime()); |
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 27 28 29 30 31 32 33 34 35 | public class StringComparision { public static void main(String[] args) { String name1 = "Namita"; String name2 = "namita"; String name3 = "Namita"; if (name1.equals(name3)) { System.out.println(name1 + " is equals to " + name3); } else { System.out.println(name1 + " is not equals to " + name3); } if (name1.equals(name2)) { System.out.println(name1 + " is equals to " + name2); } else { System.out.println(name1 + " is not equals to " + name2); } if (name1.equalsIgnoreCase(name2)) { System.out.println(name1 + " is equalsIgnoreCase to " + name2); } else { System.out.println(name1 + " is not equalsequalsIgnoreCase to " + name2); } if (name1.compareTo(name2) == 0) { System.out.println(name1 + " is equals to " + name2); } else { System.out.println(name1 + " is not equals to " + name2); } if (name1.compareToIgnoreCase(name2) == 0) { System.out.println(name1 + " is equalsIgnoreCase to " + name2); } else { System.out.println(name1 + " is not equalsequalsIgnoreCase to " + name2); } } } |
equals(Object anObject) compare String with object and returns boolean value, for comparing two strings if both are strictly equals(case sensitive) then it will return true else false value. equalsIgnoreCase(String anotherString) compare two strings with case ignorance and return boolean value. compareTo(String anotherString) compare two strings and return int value if both are equal(with case) … Read more
For listing a directory content in java we use File class and use isDirectory() method to check whether it is directory or not. if directory then we use listFiles().
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 | package io; import java.io.File; public class DirProperties { public static void main(String[] args) { File f = new File("D:\\ebhor"); if (f.exists() == false) { System.out.println("File or Directory does not exists"); if (f.mkdir()) { System.out.println("File is created"); } } if (f.isDirectory()) { System.out.println("This is a directory"); } System.out.println("Total space is " + f.getTotalSpace()); File[] f1 = f.listFiles(); for (File ff : f1) { System.out.println(ff.toString()); } } } |
1 2 3 4 5 6 7 8 9 10 | public class StringCaseChange { public static void main(String[] args) { String sentence="Welcome to Java World"; String upperSentense=sentence.toUpperCase(); System.out.println("Sentence in upper case : "+upperSentense); String lowerSentense=sentence.toLowerCase(); System.out.println("Sentence in lower case : "+lowerSentense); } } |
toUpperCase() and toLowerCase() are methods in String class which converts given string in upper and lower case respectively and return a string.
1 Swapping two numbers using third variable
1 2 3 4 5 6 7 8 9 10 11 | public class SwapExample { public static void main(String[] args) { int a = 5, b = 7; int c; System.out.println("a= " + a + " b=" + b); c = a; a = b; b = c; System.out.println("a= " + a + " b=" + b); } } |
Output
1 2 | a= 5 b=7 a= 7 b=5 |
2. Swapping two numbers without using third variable
1 2 3 4 5 6 7 8 9 10 11 | public class SwapExample1 { public static void main(String[] args) { int a = 5, b = 7; int c; System.out.println("a= " + a + " b=" + b); a = a + b; b = a-b; a=a-b; System.out.println("a= " + a + " b=" + b); } } |
Output
1 2 | a= 5 b=7 a= 7 b=5 |
3. Swapping two numbers in a single line using addition and subtraction
1 2 3 4 5 6 7 8 9 | public class SwapExample1 { public static void main(String[] args) { int a = 5, b = 7; int c; System.out.println("a= " + a + " b=" + b); b = (a + b) - (a = b); System.out.println("a= " + a + " b=" + b); } } |
Output
1 2 | a= 5 b=7 a= 7 b=5 |
4. Swapping two numbers in a single line using multiplication and division
1 2 3 4 5 6 7 8 9 10 | public class SwapExample1 { public static void main(String[] args) { int a = 5, b = 7; int c; System.out.println("a= " + a + " b=" + b); a = (a * b) / (b = a); System.out.println("a= " + a + " b=" + b); } } |
Output
1 2 | a= 5 b=7 a= 7 b=5 |
5. Swapping two numbers … Read more
To generate random numbers java users Random class and to generate integer random number nextInt(maxNo) of Random number is used the parameter maxNo specifies that this method generate a integer number between 0 and maxNo.
1 2 3 4 5 6 7 8 9 10 11 12 | import java.util.Random; public class RandomNumber { public static void main(String[] args) { int maxno=100; Random randomNo = new Random(); int no = randomNo.nextInt(maxno); System.out.print("random number is :" + no); } } |
It will generate random number between 0 and 100, where 0 and 100 are included
We are discussing java program to reverse a string using following ways Java program to reverse a string using StringBuffer or StringBuilder class Java program to reverse a string using Loops(Iteration) Java program to reverse a string using StringBuffer or StringBuilder class
1 2 3 4 5 6 7 8 9 10 11 12 | import java.util.Scanner; public class ReverseString { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.println("Enter a String"); String string = scanner.next(); StringBuilder sb = new StringBuilder(string); String reverseString = sb.reverse().toString(); System.out.println("Your String is " + string); System.out.println("Reverse String is " + reverseString); } } |
Output
1 2 3 4 | Enter a String Programming Your String is Programming Reverse String is gnimmargorP |
Java program to reverse a string using Loops(Iteration) Copy and … Read more
