Lambda expressions are introduced in Java 8 and are touted to be the biggest feature of Java 8. Lambda expression facilitates functional programming, and simplifies the development a lot.SyntaxA lambda expression is characterized by the following syntax.parameter -> expression bodyFollowing are the important characteristics of a lambda expression.Optional type declaration − No need to declare the type of a parameter. The compiler can inference the same from the value of the parameter.Optional parenthesis around parameter − No need to declare a single parameter in parenthesis. For multiple parameters, parentheses are required.Optional curly braces − No need to use curly braces ... Read More

A JavaBean is a specially constructed Java class written in the Java and coded according to the JavaBeans API specifications.Following are the unique characteristics that distinguish a JavaBean from other Java classes −It provides a default, no-argument constructor.It should be serializable and that which can implement the Serializable interface.It may have a number of properties which can be read or written.It may have a number of "getter" and "setter" methods for the properties.JavaBeans PropertiesA JavaBean property is a named attribute that can be accessed by the user of the object. The attribute can be of any Java data type, including ... Read More

Is it possible to create and run a Java program without any class? The answer is Yes. Trick is to use enum instead of Class. Although enum is used to represent public static constant. It can have static main method as well. See the example below −Example Live Demopublic enum Tester {    C, Java, PHP;    public static void main(String[] args) {       System.out.println("Programming in " + Tester.C.toString());       System.out.println("Programming in " + Tester.Java.toString());       System.out.println("Programming in " + Tester.PHP.toString());    } }OutputProgramming in C Programming in Java Programming in PHP

In order to find duplicates we can utilize the property of Set in Java that in Java duplicates are not allowed when going to be added in a Set.Add method of set returns true for the adding value which is not added previously to it while it would return false in case the adding value is already present in the Set.For our agenda we would iterate out list or collection of integer and try to add each integer in a set of type integer.Now if integer gets added than this means that it is occurring for first time and not ... Read More

In order to count upper and lower case character we have to first find weather a given character is in upper case or in lower case. For this we would take concept of ASCII value of each character in Java. In Java as we know for each character has corresponding ASCII value so we would compare each character that it lies in the range of upper case or in lower case. Counting upper and lower case characters in a string in Java In below example first convert string to a character array for easy transverse, then find weather it lies ... Read More

We can convert any decimal number to its equivalent octal by following program.In this we reserve the reminder we get after divide the given number by 8 as it is the base of Octal and then reverse the order of reminders we have stored by multiplying each reminder by 10.Let understand by following example.Example Live Demopublic class DecimalToOctal {    public static void main(String[] args) {       int decimal = 84;       int octalNumber = 0, i = 1;       while (decimal != 0) {          octalNumber += (decimal % 8) * i;          decimal /= 8;          i *= 10;       }       System.out.println("Octal of given decimal is " + octalNumber);    } }OutputOctal of given decimal is 124

In order to convert first character as upper case in a sentence we have to first separate each word of sentence and then make first character of each word in upper case.After which we have to again join each word separated by space to make again sentence.Now let take each task one by one.First in order to get each word of the sentence separately we would use Scanner class of Java and implement its hasnext method to check whether our sentence has any more word or not, in case word is present then we would get that word by using ... Read More

In order to find that a given string contains all vowels we have to first convert given string into character array so that we can simplify the comparison of each character of given string.After this put each character into a hash map so that we can check whether our map created from given string contain all vowels or not.We took help of hash map here because there is no concrete method in character array class which could check that it contains all vowels or not.Only way to check is to iterate whole array and compare each character with each vowel ... Read More

In Java there is no delegate library or API in order to write or read comma separated value(csv) file.So a 3rd party APIs are available for such requirements.Most popular 3rd party API is OpenCSV which is provide methods to deal with CSV file such as read csv file, write csv file, parse values of csv file, mapping of csv file values to java beans and java beans to csv file etc.In order to use/import this tool in Java project there are following approaches −Download the binaries/jars from http://sourceforge.net/projects/opencsv/Download through maven by updating pom.xml as    net.sf.opencsv    opencsv    2.3 ... Read More

strictfp is used to ensure that floating points operations give the same result on any platform. As floating points precision may vary from one platform to another. strictfp keyword ensures the consistency across the platforms.strictfp can be applied to class, method or on interfaces but cannot be applied to abstract methods, variable or on constructors. Following are the valid examples of strictfp usage.Examplestrictfp class Test { } strictfp interface Test { } class A {    strictfp void Test() {    } }ExampleFollowing are the invalid strictfp usage.class A {    strictfp float a; } class A {    strictfp abstract void test(); } class A {    strictfp A() {    } }