Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Object Oriented Programming Articles
Page 265 of 589
How to assign int value to char variable in Java
To assign int value to a char variable in Java would consider the ASCII value and display the associated character/ digit.Here, we have a char.char val;Now assign int value to it.val = 77;Now, when you will print the value of “val”, it would display the character associate with the value (ASCII) 77.The following is the complete example.Examplepublic class Demo { public static void main(String []args) { char val; val = 77; System.out.print("Value: "); System.out.println(val); } }OutputValue: M
Read MoreJava Program to validate if a String contains only numbers
To validate if a String has only numbers, you can try the following codes. We have used the matches() method in Java here to check for number in a string.Examplepublic class Demo { public static void main(String []args) { String str = "978"; System.out.println("Checking for string that has only numbers..."); System.out.println("String: "+str); if(str.matches("[0-9]+") && str.length() > 2) System.out.println("String has only numbers!"); else System.out.println("String consist of characters as well!"); } }OutputChecking for string that has only numbers... String: ...
Read MoreCheck whether the entered value is a letter or not in Java
To check whether the entered value is a letter or not in Java, use the Character.isLetter() method.We have a value to be checked.char val = 'D';Now let us use the Character.isLetter() method.if (Character.isLetter(val)) { System.out.println("Character is in Lowercase!"); }else { System.out.println("Character is in Uppercase!"); }Let us see the complete example now to check for letter.Examplepublic class Demo { public static void main(String []args) { System.out.println("Checking whether the given value is a Letter or not..."); char val = 'D'; System.out.println("Value: "+val); if (Character.isLetter(val)) { ...
Read MoreJava Program to check whether the entered character a digit, white space, lower case or upper case character
To check whether the entered character is a digit, whitespace, lowercase or uppercase, you need to check for the ASCII values.Let’s say we have a value in variable “val”, which is to be checked.For Lower Case.if(val >= 97 && val = 65 && val = 48 && val = 97 && val = 65 && val = 48 && val = 97 && val = 65 && val = 48 && val
Read MoreStore unicode in a char variable in Java
To store Unicode in a char variable, simply create a char variable.char c;Now assign unicode.char c = '\u00AB';The following is the complete example that shows what will get displayed: when Unicode is stored in a char variable and displayed.Examplepublic class Demo { public static void main(String []args) { int a = 79; System.out.println(a); char b = (char) a; System.out.println(b); char c = '\u00AB'; System.out.println(c); } }Output79 O «
Read MoreConvert string to char array in Java
The following is our string.String str = "Tutorial";Now, use the toCharArray() method to convert string to char array.char[] ch = str.toCharArray();Now let us see the complete example.Examplepublic class Demo { public static void main(String []args) { String str = "Tutorial"; System.out.println("String: "+str); char[] ch = str.toCharArray(); System.out.println("Character Array..."); for (int i = 0; i < ch.length; i++) { System.out.print(ch[i]+" "); } } }OutputString: Tutorial Character Array... T u t o r i a l
Read MoreDetermine if a String is a legal Java Identifier
To determine if a String is a legal Java Identifier, use the Character.isJavaIdentifierPart() and Character.isJavaIdentifierStart() methods.Character.isJavaIdentifierPart()The java.lang.Character.isJavaIdentifierPart() determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.A character may be part of a Java identifier if any of the following are true.it is a letterit is a currency symbol (such as '$')it is a connecting punctuation character (such as '_')it is a digitit is a numeric letter (such as a Roman numeral character)Character.isJavaIdentifierStart()The java.lang.Character.isJavaIdentifierStart() determines if the character (Unicode code point) is permissible as the first character in a Java ...
Read MoreHow to prevent Cloning to break a Singleton Class Pattern in Java?
A Singleton pattern states that a class can have a single instance and multiple instances are not permitted to be created. For this purpose, we make the constructor of the class a private and return a instance via a static method. But using cloning, we can still create multiple instance of a class. See the example below − Example - Breaking Singleton public class Tester{ public static void main(String[] args) throws CloneNotSupportedException { A a = A.getInstance(); ...
Read MorePrivate Constructors and Singleton Classes in Java Programming
As we know the primary role of the constructor is to instantiate a class object now if we made the constructor as private then we restrict its calling to be only in defining a class and not in some other class. Now the singleton class in Java is defined as the class which restricts the instantiation of a class and ensure that only one instance of the class exists in the JVM. After first time if instantiate the singleton class the new variable also points to the first instance created. In order to create a singleton class we could use ...
Read MorePrivate and final methods in Java Programming
In Java private methods are the methods having private access modifier and are restricted to be access in the defining class only and are not visible in their child class due to which are not eligible for overridden. However, we can define a method with the same name in the child class and could access in parent class.Like private methods final methods in Java are the methods having final non-access modifier instead of private and are again restricted to be accessed in the defining class only and are not visible in their child class due to which are not eligible ...
Read More