- Why do we use a constructor?
- What does @override do in java?
- What does *= mean in Java?
- What does * do in Java?
- What does \\ s+ mean in Java?
- What is symbol called in Java?
- What is S in Java?
- What is difference between i ++ and ++ i in Java?
- What is :: operator in Java?
- What does a zA Z0 9 mean?
- What does * do in regex?
Why do we use a constructor?
The purpose of constructor is to initialize the object of a class while the purpose of a method is to perform a task by executing java code.
Constructors cannot be abstract, final, static and synchronised while methods can be.
Constructors do not have return types while methods do..
What does @override do in java?
@Override @Override annotation informs the compiler that the element is meant to override an element declared in a superclass. Overriding methods will be discussed in Interfaces and Inheritance. While it is not required to use this annotation when overriding a method, it helps to prevent errors.
What does *= mean in Java?
binary operatorIn Java “*=” is a shorthand operator or a shorter way to express an operation that already exists in the language. … It is a binary operator. That means, it has two operands, one on the left and other on the right.
What does * do in Java?
The Arithmetic OperatorsOperatorDescription* (Multiplication)Multiplies values on either side of the operator./ (Division)Divides left-hand operand by right-hand operand.% (Modulus)Divides left-hand operand by right-hand operand and returns remainder.++ (Increment)Increases the value of operand by 1.3 more rows
What does \\ s+ mean in Java?
\s – matches single whitespace character. \s+ – matches sequence of one or more whitespace characters.
What is symbol called in Java?
6 Answers. The @ symbol denotes a Java Annotation. What a Java annotation does, is that it adds a special attribute to the variable, method, class, interface, or other language elements.
What is S in Java?
The string \s is a regular expression that means “whitespace”, and you have to write it with two backslash characters ( “\\s” ) when writing it as a string in Java.
What is difference between i ++ and ++ i in Java?
What is the Difference Between i++ and ++i in Java? ++i and i++ both increment the value of i by 1 but in a different way. If ++ precedes the variable, it is called pre-increment operator and it comes after a variable, it is called post-increment operator.
What is :: operator in Java?
The double colon (::) operator, also known as method reference operator in Java, is used to call a method by referring to it with the help of its class directly. … The only difference it has from lambda expressions is that this uses direct reference to the method by name instead of providing a delegate to the method.
What does a zA Z0 9 mean?
The bracketed characters [a-zA-Z0-9] mean that any letter (regardless of case) or digit will match. … The _ (underscore) character in the regular expression means that the zone name must have an underscore immediately following the alphanumeric string matched by the preceding brackets.
What does * do in regex?
* : An asterisk is used to match the preceding character zero or more times. So the regex . * would match any string at all as long as it did not contain a newline character.