Java Articles - Page 592 of 745

To display the day in week, use the SimpleDateFormat(“E”) as shown below −Format f = new SimpleDateFormat("E"); String strDayinWeek = f.format(new Date()); System.out.println("Day in week = "+strDayinWeek);Since, we have used the Format and SimpleDateFormat class above, therefore import the following packages. With that, we have also used the Date.import java.text.Format; import java.text.SimpleDateFormat; import java.util.Date;Example Live Demoimport java.text.Format; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Calendar; public class Demo {    public static void main(String[] args) throws Exception {       // displaying current date and time       Calendar cal = Calendar.getInstance();       SimpleDateFormat simpleformat = new SimpleDateFormat("dd/MMMM/yyyy hh:mm:s"); ... Read More

To display two-digit day number, use the SimpleDateFormat('dd') as shown below −// displaying two-digit day number f = new SimpleDateFormat("dd"); String strDay = f.format(new Date()); System.out.println("Day Number = "+strDay);Since, we have used the Format and SimpleDateFormat class above, therefore import the following packages. With that, we have also used the Date.import java.text.Format; import java.text.SimpleDateFormat; import java.util.Date;The following is an example.Example Live Demoimport java.text.Format; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Calendar; public class Demo {    public static void main(String[] args) throws Exception {       // displaying current date and time       Calendar cal = Calendar.getInstance();       ... Read More

In Java, verifying whether a string is a valid number is a common requirement in various applications. This process ensures that the string can be safely converted to a numerical type without causing runtime exceptions. To validate if a string can be converted to these types, we use the Integer.parseInt() and Float.parseFloat() methods, respectively. Problem Statement Given a string that may contain an integer or a float value, write a Java program to check whether it is valid number or not. Input "100" //string value Output 100 // ... Read More

Float is a wrapper class provided to wrap float primitive value.Let us create a Float object with float primitive.// float primitive float myFloat = 24.22f; // Float object Float obj1 = new Float(myFloat);Let us now create a Float object from string.Float obj2 = new Float("39.87");The following is an example that displays both the ways discussed above with output.Example Live Demoimport java.lang.*; public class Demo {    public static void main(String args[]) {       float myFloat = 24.22f;       Float obj1 = new Float(myFloat);       System.out.println(obj1);       Float obj2 = new Float("39.87");       System.out.println(obj2);    } }Output24.22 39.87

The isNan() method returns true if the Float value is a Not-a-Number (NaN). Let’s say we have the following Float values.Float f1 = new Float(5.0/0.0); Float f2 = new Float(10.2/0.0); Float f3 = new Float(0.0/0.0);Check with isNaN() method.f1.isNaN (); f2.isNaN (); f3.isNaN ();The following is the complete example with output.Example Live Demoimport java.lang.*; public class Demo {    public static void main(String args[]) {       Float f1 = new Float(5.0/0.0);       Float f2 = new Float(10.2/0.0);       Float f3 = new Float(0.0/0.0);       System.out.println(f1.isNaN());       System.out.println(f2.isNaN());       System.out.println(f3.isNaN());   ... Read More

To convert decimal integer to hexadecimal, use the Integer.toHexString() method. Let’s say the following is our decimal integer.int decInt = 25;The following is the usage of the Integer.toHexString() method to convert decimal integer to hexadecimal number.String myHex = Integer.toHexString(decInt);The following the complete example.Example Live Demopublic class Demo {    public static void main(String []args) {       int decInt = 25;       System.out.println("Decimal Integer = "+decInt);       String myHex = Integer.toHexString(decInt);       System.out.println("Hexadecimal = "+myHex);    } }OutputDecimal Integer = 25 Hexadecimal = 19

To convert octal to decimal number, use the Integer.parseInt() method with radix 8. Here, the radix is for Octal i.e. 8.Let’s say we have the following octal string.String myOctal = "25";To convert it to decimal, use the Integer.parseInt() method.int val = Integer.parseInt(myOctal, 8);The following is the complete example.Example Live Demopublic class Demo {    public static void main(String []args) {       String myOctal = "25";       System.out.println("Octal = "+myOctal);       int val = Integer.parseInt(myOctal, 8);       System.out.println("Decimal = "+val);    } }OutputOctal = 25 Decimal = 21

In this article, we will learn to decode string to integer in Java. Converting a string to an integer is a routine task in Java programming. It is helpful when working with user inputs, file operations, and data fetching from databases. Problem Statement The goal is to convert a given string representation of a number into an integer. For ExampleInput String val = "2"; Output Integer = 2 Different Approaches The following are the two different approaches to decode string to integer in Java − Using Integer.decode() Using Integer.parseInt() Using ... Read More

To convert String to long, the following are the two methods.Method 1The following is an example wherein we use parseLong() method.Example Live Demopublic class Demo {    public static void main(String[] args) {       String myStr = "5";       Long myLong = Long.parseLong(myStr);       System.out.println("Long: "+myLong);    } }OutputLong: 5Method 2The following is an example wherein we have used valueOf() and longValue() method to convert String to long.Example Live Demopublic class Demo {    public static void main(String[] args) {       String myStr = "20";       long res = Long.valueOf(myStr).longValue();       System.out.println("Long: "+res);    } }OutputLong: 20

To check for Long overflow, we need to check the Long.MAX_VALUE with the multiplied long result, Here, Long.MAX_VALUE is the maximum value of the Long type in Java. Let us see an example wherein long values are multiplied and if the result is more than the Long.MAX_VALUE, then an exception is thrown. Steps to multiply long integers and check for overflow Following are the steps to multiply long integers and check for overflow in Java − Initialize long values by defining two long integers, val1 and val2. Multiply val1 and val2 to ... Read More