Call by Value means calling a method with a parameter as value. Through this, the argument value is passed to the parameter.While Call by Reference means calling a method with a parameter as a reference. Through this, the argument reference is passed to the parameter.In call by value, the modification done to the parameter passed does not reflect in the caller's scope while in the call by reference, the modification done to the parameter passed are persistent and changes are reflected in the caller's scope. But Java uses only call by value. It creates a copy of references and pass ... Read More

Call by Value means calling a method with a parameter as value. Through this, the argument value is passed to the parameter.While Call by Reference means calling a method with a parameter as a reference. Through this, the argument reference is passed to the parameter.In call by value, the modification done to the parameter passed does not reflect in the caller's scope while in the call by reference, the modification done to the parameter passed are persistent and changes are reflected in the caller's scope. But Java uses only call by value. It creates a copy of references and pass ... Read More

When you compile Java programs using javac compiler it generates bytecode. We need to execute this bytecode using JVM (Java Virtual machine) Then, JVM translates the Java bytecode to machine understandable code. You can download JVM's (comes along with JDK or JRE) suitable to your operating system and, once you write a Java program you can run it on any system using JVM.

When you compile Java programs using javac compiler it generates bytecode. We need to execute this bytecode using JVM (Java Virtual machine) Then, JVM translates the Java bytecode to machine understandable code. You can download JVM's (comes along with JDK or JRE) suitable to your operating system and, once you write a Java program you can run it on any system using JVM.

Following example uses iterator Method of Collection class to iterate through the HashMap.Example Live Demoimport java.util.*; public class Main {    public static void main(String[] args) {       HashMap< String, String> hMap = new HashMap< String, String>();       hMap.put("1", "1st");       hMap.put("2", "2nd");       hMap.put("3", "3rd");       Collection cl = hMap.values();       Iterator itr = cl.iterator();       while (itr.hasNext()) {          System.out.println(itr.next());       }    } }OutputThe above code sample will produce the following result.1st 2nd 3rd

Following example uses iterator Method of Collection class to iterate through the HashMap.Example Live Demoimport java.util.*; public class Main {    public static void main(String[] args) {       HashMap< String, String> hMap = new HashMap< String, String>();       hMap.put("1", "1st");       hMap.put("2", "2nd");       hMap.put("3", "3rd");       Collection cl = hMap.values();       Iterator itr = cl.iterator();       while (itr.hasNext()) {          System.out.println(itr.next());       }    } }OutputThe above code sample will produce the following result.1st 2nd 3rd

Following example compares two strings by using str compareTo (string), str compareToIgnoreCase(String) and str compareTo(object string) of string class and returns the ascii difference of first odd characters of compared strings.Example Live Demopublic class StringCompareEmp{    public static void main(String args[]) {       String str = "Hello World";       String anotherString = "hello world";       Object objStr = str;       System.out.println( str.compareTo(anotherString) );       System.out.println( str.compareToIgnoreCase(anotherString) );       System.out.println( str.compareTo(objStr.toString()));    } }OutputThe above code sample will produce the following result.-32 0 0String compare by equals()This method compares ... Read More

Following example compares two strings by using str compareTo (string), str compareToIgnoreCase(String) and str compareTo(object string) of string class and returns the ascii difference of first odd characters of compared strings.Example Live Demopublic class StringCompareEmp{    public static void main(String args[]) {       String str = "Hello World";       String anotherString = "hello world";       Object objStr = str;       System.out.println( str.compareTo(anotherString) );       System.out.println( str.compareToIgnoreCase(anotherString) );       System.out.println( str.compareTo(objStr.toString()));    } }OutputThe above code sample will produce the following result.-32 0 0String compare by equals()This method compares ... Read More

We can generate random numbers using three ways in Java.Using java.util.Random class − Object of Random class can be used to generate random numbers using nextInt(), nextDouble() etc. methods.Using java.lang.Math class − Math.random() methods returns a random double whenever invoked.Using java.util.concurrent.ThreadLocalRandom class − ThreadLocalRandom.current().nextInt() method and similar othjer methods return a random numbers whenever invoked.Exampleimport java.util.Random; import java.util.concurrent.ThreadLocalRandom; public class Tester {    public static void main(String[] args) {       generateUsingRandom();       generateUsingMathRandom();       generateUsingThreadLocalRandom();    }    private static void generateUsingRandom() {       Random random = new Random(); ... Read More

We can generate random numbers using three ways in Java.Using java.util.Random class − Object of Random class can be used to generate random numbers using nextInt(), nextDouble() etc. methods.Using java.lang.Math class − Math.random() methods returns a random double whenever invoked.Using java.util.concurrent.ThreadLocalRandom class − ThreadLocalRandom.current().nextInt() method and similar othjer methods return a random numbers whenever invoked.Exampleimport java.util.Random; import java.util.concurrent.ThreadLocalRandom; public class Tester {    public static void main(String[] args) {       generateUsingRandom();       generateUsingMathRandom();       generateUsingThreadLocalRandom();    }    private static void generateUsingRandom() {       Random random = new Random(); ... Read More