Public void java code

Example of Java code with a public void function that takes an integer parameter

As a substitute for C# delegates, Java commonly employs anonymous inner classes. However, it’s important to note that classes cannot be distinguished solely based on their generic type parameters.

Public void set in Java; What is it exactly?

A declaration of a method, identified by public void set(String s, int value) , is accompanied by a method body within < and ends with >.

public void set(String s, int value) \____/ \__/ \_/ | | | | | '---- Method name | | | '-------- Method return type | '-------------- Access modifier 

The statement following the < line:

This involves invoking a method, specifically the set , and passing in s and new Integer(value) as parameters.

Like any other method, set has no unique semantics. It may function similarly to Map.put , registering the given value under the string key, or it could execute an entirely different set of actions, such as starting multiple threads to compute the significance of life.

The method that is invoked within the declaration as the «other» method could have a specific signature.

set(String key, Object value) 

set(String key, Integer value) 

Either option is suitable, but I prefer the former because the latter may be unnecessary with autoboxing.

A function is defined with the scope of public which allows it to be called from outside the class. The return type of the function is specified by void and if there is no return value, it is indicated by void. The name of the function is set.

The Method appears to serve as an interface for externally assigning any variable a specific value. This is achieved by invoking another Method called ‘set’ with a String and a new Integer-Object that contains the desired value. It is possible that this is done to access another overloaded function with a similar signature.

private void set(String s, Integer value) 

It may be helpful to search for something similar, as this could potentially clarify your code.

Public void set in Java; What is it exactly?, 0. it’s a function. public is the scope where the function is reachable (in this case you can call it from outside of the class), void is the return type, while void means there is no return value. set is the name of the function. The Method seems to be a kind of interface to set any variable to the given value from …

Java’s equivalents of Func and Action

Java 8 offers the counterparts of java.util.function.Function and java.util.function.Consumer through the use of interfaces. Additionally, System.Predicate serves as the equivalent of java.util.function.Predicate . It’s worth noting that these are interfaces rather than delegates, as previously mentioned.

As a related note, I am currently relying significantly on a utility class that enables me to perform LINQ-like extension method operations.

abstract class IterableUtil < public static Iterable where(Iterable items, Predicate predicate) < ArrayListresult = new ArrayList(); for (T item : items) < if (predicate.test(item)) < result.add(item); >> return result; > public static Iterable select(Iterable items, Function func) < ArrayListresult = new ArrayList(); for (T item : items) < result.add(func.apply(item)); >return result; > > 

The LINQ-style techniques that I am introducing here do not exhibit laziness like System.Linq.Enumerable.Where and System.Linq.Enumerable.Select . They exhaustively explore the source collections before providing the output collections to the caller. Nevertheless, I consider them valuable for their purely syntactic benefits, and they could be made lazy if required. This is based on the premise that we have.

List widgets = /* . */; Iterable filteredWidgets = IterableUtil.where(widgets, w -> w.name().startsWith("some-prefix")); 

Which I prefer to the following:

List widgets = /* . */; List filteredWidgets = new ArrayList(); for (Widget w : widgets) < if (w.name().startsWith("some-prefix")) < filteredWidgets.add(w); >> 

The Callable interface bears resemblance to the Func interface.

The functionality of the Runnable interface resembles that of the Action interface.

Generally, in Java, anonymous inner classes are utilized instead of C# delegates. As an illustration, this is the approach for adding code to respond to a button press in a GUI.

button.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < . //code that reacts to the action. >>); 

Apart from the issue of delegate versus anonymous class, the overloaded Func delegates are elegant as they can handle a range of arguments, starting from 0 and going up to 16, such as Func , Func , Func , and so on.

Regrettably, due to type erasure in Java, it is not achievable as classes cannot be distinguished solely based on their generic type parameters.

In Java 8, new names like BiConsumer are introduced for Action , and BiIntConsumer is used as primitive type arguments are not allowed. However, while the number of names in this «zoo» is limited, there is currently no library that expands it. A proposal for function type literals, such as (int, int) => void , was suggested but ultimately not accepted.

Java void Keyword, Java Examples Java Compiler Java Exercises Java Quiz Java Certificate. Java void Keyword Java Keywords. Example. A method without any return values: public class Main < static void myMethod() < System.out.println("I just got executed!"); >Example public class Main < static int myMethod(int x) < return 5 + x; >public …

Passing a func condition in java

In case you are wondering about the way to invoke the method, one option is to utilize an instance of Function by using the following syntax:

ClickAndWaitForCondition(by, new Function  < @Override public Boolean apply(Boolean aBoolean) < //do your magic here return !aBoolen; //example: negation >>); 

You can either invoke it by using a lambda expression, as shown in the example of negation.

ClickAndWaitForCondition(by, a->!a); 

You mentioned that the function accepts a boolean and then returns a boolean, however, your code doesn’t seem to follow this pattern. This is because of the Function type, which enables you to make the following invocation.

if (condition.apply(true) == false) break; 

The snippet you pasted may not be valid Java because everything is capitalized. However, I’m not sure if that’s what’s causing confusion. To clarify, in Java, all keywords are in lowercase, including break; , if , for , public , and void . It’s important to note that Java is case sensitive for all of these keywords.

Your code is good except for the boolean parameter required by the apply method and the capitalization issue.

In case you’re searching for a function that returns a boolean and doesn’t require any parameters, as demonstrated in the code snippet, there is such a function available, which is represented by java.util.function.Supplier .

By combining everything and utilizing the standard Java practices,

public void clickAndWaitForCondition(By locator, Supplier condition) < Webdriver.findElement(locator).click(); for (int i = 0; i > > 

Selenium offers a waiting mechanism that can be utilized if you need to click and wait for a certain condition.

abstract class ClickAndWait implements Function  < By by; public ClickAndWait(By by)< this.by = by; >abstract boolean checkCondition(SearchContext context); @Override public Boolean apply(SearchContext context) < context.findElement(by).click(); return checkCondition(context); >> 

@Test public void testClickAndWait() < Waitwaiter = new FluentWait<>(driver); waiter.until(new ClickAndWait(By.xpath("//PATH_TO_YOUR_ELEMENT")) < @Override boolean checkCondition(SearchContext context) < // Evaluate conditions here; return true; >>); > 

Additional instances of waiting for conditions in Selenium can be reviewed.

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Java void Keyword

The void keyword specifies that a method should not have a return value.

More Examples

Tip: If you want a method to return a value, you can use a primitive data type (such as int , char , etc.) instead of void , and use the return keyword inside the method:

Example

public class Main < static int myMethod(int x) < return 5 + x; > public static void main(String[] args) < System.out.println(myMethod(3)); >> // Outputs 8 (5 + 3) 

Related Pages

Read more about methods in our Java Methods Tutorial.

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public static void main(String[] args) — Java main method

The Java main method is usually the first method you learn about when you start programming in Java because its the entry point for executing a Java program. The main method can contain code to execute or call other methods, and it can be placed in any class that’s part of a program. More complex programs usually have a class that contains only the main method. The class that contains the main method can have any name, although typically you can just call the class Main .

In the examples that follow, the class that contains the main method is called Test :

public class Test  public static void main(String[] args) System.out.println("Hello, World!"); > > 

In this article you’ll learn what each component of the main method means.

Java Main Method Syntax

The syntax of the main method is always:

public static void main(String[] args) // some code > 

You can change only the name of the String array argument. For example, you can change args to myStringArgs . The String array argument can be written as String. args or String args[] .

public

The access modifier of the main method needs to be public so that the JRE can access and execute this method. If a method isn’t public, then access is restricted. In the following example code, the main method is missing the public access modifier:

public class Test  static void main(String[] args) System.out.println("Hello, World!"); > > 

When you compile and run the program, the following error occurs because the main method isn’t public and the JRE can’t find it:

Output
Error: Main method not found in class Test, please define the `main` method as: public static void main(String[] args) or a JavaFX application class must extend javafx.application.Application 

static

When the Java program starts, there is no object of the class present. The main method has to be static so that the JVM can load the class into memory and call the main method without creating an instance of the class first. In the following example code, the main method is missing the static modifier:

public class Test  public void main(String[] args) System.out.println("Hello, World!"); > > 

When you compile and run the program, the following error occurs because the main method isn’t static :

Output
Error: Main method is not static in class Test, please define the `main` method as: public static void main(String[] args) 

void

Every Java method must provide the return type. The Java main method return type is void because it doesn’t return anything. When the main method is finished executing, the Java program terminates, so there is no need for a returned object. In the following example code, the main method attempts to return something when the return type is void :

public class Test  public static void main(String[] args) return 0; > > 

When you compile the program, the following error occurs because Java doesn’t expect a return value when the return type is void :

Output
Test.java:5: error: incompatible types: unexpected return value return 0; ^ 1 error 

main

The Java main method is always named main . When a Java program starts, it always looks for the main method. The following example code shows a main method renamed to myMain :

public class Test  public static void myMain(String[] args) System.out.println("Hello, World!"); > > 

When you compile and run the program, the following error occurs because the JRE can’t find the main method in the class:

Output
Error: Main method not found in class Test, please define the `main` method as: public static void main(String[] args) or a JavaFX application class must extend javafx.application.Application 

String[] args

Java main method accepts a single argument of type String array. Each string in the array is a command line argument. You can use command line arguments to affect the operation of the program, or to pass information to the program, at runtime. The following example code shows how to print the command line arguments that you enter when you run the program:

public class Test  public static void main(String[] args) for(String s : args) System.out.println(s); > > > 

When you compile the program and then run it with a few command line arguments separated by spaces, the arguments get printed in the terminal:

Output
1 2 3 Testing the main method 

Conclusion

In this article you learned about each component of the Java main method. Continue your learning with more Java tutorials.

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