void Keyword in Java
void – returns nothing.
The void keyword in Java is used to specify that a method does not return any value. It is a return type that indicates the method performs an action but does not produce a result that can be used elsewhere in the code.
Usage
The void keyword is typically used in method declarations. When a method is declared with a void return type, it means that the method will not return any value.
Syntax
void methodName(parameters) {
// method body
}
Reference:https://www.datacamp.com/doc/java/void
What is void?
Void is a return datatype which means nothing is returned from a method, to the method calling statement.
return keyword in Java
In Java, return is a reserved keyword i.e., we can’t use it as an identifier. It is used to exit from a method, with or without a value. Usage of return keyword as there exist two ways as listed below as follows:
Case 1: Methods returning a value Case 2: Methods not returning a value
Reference:https://www.geeksforgeeks.org/return-keyword-java/
Return:
*#return is a java keyword. This keyword is used to return any value from a method. Returned value will be sent back to Method Calling Statement. *
#Return statement should be the last statement in a method definition. We should not give anyother expression or statement, after return in methods.
Can we return multiple values in Java?
Yes, we can return multiple values from a method in Java. To return multiple values, we need to use Arrays or Collection.
Is there any language which returns multiple values from a method?
Yes, In Python we can return multiple values. It will be stored as tuple.
*Task 1: *
Goal: Learning Method Return datatype
- Create a class Kitchen
- Have main method in it.
- Create an instance called 'father'.
- Using father instance, call method 'cook' with no arguments.
- Now, return "biryani" from cook method.
- Save, Compile and Check the error message
- Based on the error message, change return datatype accordigly.
- Store returned value as 'fav_dish' in main method.
- Print 'fav_dish' in main method.
Program
public class Kitchen
{
public static void main(String[] args)
{
Kitchen father = new Kitchen();
String favDish=father.cook();
System.out.println("FAV DISH ="+favDish);
}
public String cook()
{
return"briyani";
}
}
Output
neelakandan@neelakandan-HP-Laptop-15s-eq2xxx:~/Documents/B14$ java Kitchen FAV DISH =briyani neelakandan@neelakandan-HP-Laptop-15s-eq2xxx:~/Documents/B14$
*Task 2: *
1.Learning Method with Integer Return Type
2.Create a class named MathOperations.
3.Add a method addNumbers that accepts two integer arguments and returns their sum.
4.In the main method:
#Create an instance named calculator.
5.Call the addNumbers method with two integers, e.g., 5 and 10.
6.Store the returned value in a variable result.
7.Print result.
Program
Case 1: Methods returning a value Case 2: Methods not returning a value
Output:
public class Kitchen
{
public static void main(String[] args)
{
Kitchen father = new Kitchen();
String favDish=father.cook();
System.out.println("FAV DISH ="+favDish);
}
public String cook()
{
return"briyani";
}
}
The above is the detailed content of Today class-eturn,Task-ask-2. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Difference between HashMap and Hashtable?
Jun 24, 2025 pm 09:41 PM
The difference between HashMap and Hashtable is mainly reflected in thread safety, null value support and performance. 1. In terms of thread safety, Hashtable is thread-safe, and its methods are mostly synchronous methods, while HashMap does not perform synchronization processing, which is not thread-safe; 2. In terms of null value support, HashMap allows one null key and multiple null values, while Hashtable does not allow null keys or values, otherwise a NullPointerException will be thrown; 3. In terms of performance, HashMap is more efficient because there is no synchronization mechanism, and Hashtable has a low locking performance for each operation. It is recommended to use ConcurrentHashMap instead.
What are static methods in interfaces?
Jun 24, 2025 pm 10:57 PM
StaticmethodsininterfaceswereintroducedinJava8toallowutilityfunctionswithintheinterfaceitself.BeforeJava8,suchfunctionsrequiredseparatehelperclasses,leadingtodisorganizedcode.Now,staticmethodsprovidethreekeybenefits:1)theyenableutilitymethodsdirectly
How does JIT compiler optimize code?
Jun 24, 2025 pm 10:45 PM
The JIT compiler optimizes code through four methods: method inline, hot spot detection and compilation, type speculation and devirtualization, and redundant operation elimination. 1. Method inline reduces call overhead and inserts frequently called small methods directly into the call; 2. Hot spot detection and high-frequency code execution and centrally optimize it to save resources; 3. Type speculation collects runtime type information to achieve devirtualization calls, improving efficiency; 4. Redundant operations eliminate useless calculations and inspections based on operational data deletion, enhancing performance.
What is an instance initializer block?
Jun 25, 2025 pm 12:21 PM
Instance initialization blocks are used in Java to run initialization logic when creating objects, which are executed before the constructor. It is suitable for scenarios where multiple constructors share initialization code, complex field initialization, or anonymous class initialization scenarios. Unlike static initialization blocks, it is executed every time it is instantiated, while static initialization blocks only run once when the class is loaded.
What is the Factory pattern?
Jun 24, 2025 pm 11:29 PM
Factory mode is used to encapsulate object creation logic, making the code more flexible, easy to maintain, and loosely coupled. The core answer is: by centrally managing object creation logic, hiding implementation details, and supporting the creation of multiple related objects. The specific description is as follows: the factory mode handes object creation to a special factory class or method for processing, avoiding the use of newClass() directly; it is suitable for scenarios where multiple types of related objects are created, creation logic may change, and implementation details need to be hidden; for example, in the payment processor, Stripe, PayPal and other instances are created through factories; its implementation includes the object returned by the factory class based on input parameters, and all objects realize a common interface; common variants include simple factories, factory methods and abstract factories, which are suitable for different complexities.
What is type casting?
Jun 24, 2025 pm 11:09 PM
There are two types of conversion: implicit and explicit. 1. Implicit conversion occurs automatically, such as converting int to double; 2. Explicit conversion requires manual operation, such as using (int)myDouble. A case where type conversion is required includes processing user input, mathematical operations, or passing different types of values ??between functions. Issues that need to be noted are: turning floating-point numbers into integers will truncate the fractional part, turning large types into small types may lead to data loss, and some languages ??do not allow direct conversion of specific types. A proper understanding of language conversion rules helps avoid errors.
Why do we need wrapper classes?
Jun 28, 2025 am 01:01 AM
Java uses wrapper classes because basic data types cannot directly participate in object-oriented operations, and object forms are often required in actual needs; 1. Collection classes can only store objects, such as Lists use automatic boxing to store numerical values; 2. Generics do not support basic types, and packaging classes must be used as type parameters; 3. Packaging classes can represent null values ??to distinguish unset or missing data; 4. Packaging classes provide practical methods such as string conversion to facilitate data parsing and processing, so in scenarios where these characteristics are needed, packaging classes are indispensable.
What is the `final` keyword for variables?
Jun 24, 2025 pm 07:29 PM
InJava,thefinalkeywordpreventsavariable’svaluefrombeingchangedafterassignment,butitsbehaviordiffersforprimitivesandobjectreferences.Forprimitivevariables,finalmakesthevalueconstant,asinfinalintMAX_SPEED=100;wherereassignmentcausesanerror.Forobjectref
