Java Articles - Page 612 of 745

Every data type in Java has a minimum as well as maximum range, for example, for Float.Min = 1.4E-45 Max = 3.4028235E38Let’s say for Float, if the value extends the maximum range displayed above, it leads to Overflow.However, if the value is less than the minimum range displayed above, it leads to Underflow.The following is the Java Program to display the minimum and maximum value of primitive data types.Example Live Demopublic class Demo {    public static void main(String[] args) {       System.out.println("Integer Datatype values...");       System.out.println("Min = " + Integer.MIN_VALUE);       System.out.println("Max = " ... Read More

Primitive datatypes are predefined by the language and named by a keyword in Java. Here is an example to display the default value of primitive data types.Example Live Demopublic class Demo {    static boolean val1;    static double val2;    static float val3;    static int val4;    static long val5;    static String val6;    public static void main(String[] args) {       System.out.println("Default values.....");       System.out.println("Val1 = " + val1);       System.out.println("Val2 = " + val2);       System.out.println("Val3 = " + val3);       System.out.println("Val4 = " + val4);   ... Read More

A stack and a heap are used for memory allocation in Java. However, the stack is used for primitive data types, temporary variables, object addresses etc. The heap is used for storing objects in memory.Stacks and heaps in Java are explained in more detail as follows −Stack in JavaStacks are used to store temporary variables, primitive data types etc. A block in the stack exists for a variable only as long as the variable exists. After that, the block data is erased and it can be used for storing another variable.

This example shows how to search the minimum and maximum element in an array by using Collection.max() and Collection.min() methods of Collection class.Example Live Demoimport java.util.Arrays; import java.util.Collections; public class Main {    public static void main(String[] args) {       Integer[] numbers = { 8, 2, 7, 1, 4, 9, 5};       int min = (int) Collections.min(Arrays.asList(numbers));       int max = (int) Collections.max(Arrays.asList(numbers));       System.out.println("Min number: " + min);       System.out.println("Max number: " + max);    } }OutputThe above code sample will produce the following result.Min number: 1 Max number: 9Another ... Read More

In order to get frequency of each in a string in Java we will take help of hash map collection of Java.First convert string to a character array so that it become easy to access each character of string.Now compare for each character that whether it is present in hash map or not in case it is not present than simply add it to hash map as key and assign one as its value.And if character is present than find its value which is count of occurrence of this character in the string (initial we put as 1 when it ... Read More

Fibonacci numbers of Fibonacci series grows exponentially and can be very large for large numbers like 500 or 1000. To handle such number, long data type is not sufficient. BigInteger can handle large number easily. BigInteger is useful in scenarios where calculations results in data which is out of limit for available primitive data types. See the example below of getting Fibonacci number of 100 and 1000.Example Live Demoimport java.math.BigInteger; public class Tester {    public static void main(String args[]) {       System.out.println("Fibonacci of 100: ");       System.out.println(fibonacci(100));       System.out.println("Fibonacci of 1000: ");     ... Read More

As we know that Java needs main() method to be static in the public class to make it executable. The prime reason for this requirement is to make JVM enable to call the main() method without creating an object. That simply means that JVM does not create the object of the Main class which contains the main() method. To justify the same, we can make the Main class containing the main method as abstract and program still runs.Following example showcases the same. Here we have made the main class abstract.Exampleabstract public class Tester {    public static void main(String args[]) ... Read More

x++ automatically handles the type casting where as x= x + 1 needs typecasting in case of x is not an int variable. See the example below.Example Live Demopublic class Tester {    public static void main(String args[]) {       byte b = 2;       //Type casting is required       //as 1 is int and b is byte variable       b = (byte) (b + 1);       System.out.println(b);       byte b1 = 2;       //Implcit type casting by the compiler       b1++;       System.out.println(b1);    } }Output3 3

HashMap, TreeMap and LinkedHashMap all implements java.util.Map interface and following are their characteristics.HashMapHashMap has complexity of O(1) for insertion and lookup.HashMap allows one null key and multiple null values.HashMap does not maintain any order.TreeMapTreeMap has complexity of O(logN) for insertion and lookup.TreeMap does not allow null key but allow multiple null values.TreeMap maintains order. It stores keys in sorted and ascending order.LinkedHashMapLinkedHashMap has complexity of O(1) for insertion and lookup.LinkedHashMap allows one null key and multiple null values.LinkedHashMap maintains order in which key-value pairs are inserted.Example Live Demoimport java.util.HashMap; import java.util.Hashtable; import java.util.LinkedHashMap; import java.util.Map; import java.util.TreeMap; public class Tester { ... Read More

A helper class serve the following purposes.Provides common methods which are required by multiple classes in the project.Helper methods are generally public and static so that these can be invoked independently.Each methods of a helper class should work independent of other methods of same class.Following example showcases one such helper class.Examplepublic class Tester {    public static void main(String[] args) {       int a = 37;       int b = 39;       System.out.println(a + " is prime: " + Helper.isPrime(a));       System.out.println(b + " is prime: " + Helper.isPrime(b));    } } ... Read More