Question

when we need to use a class name as a datatype for methods in java? explain in details with helpful of examples

Answer 1

Class name is used as data type in java methods in the following situations :

1. When we need to pass instance of a particular class as argument to a method, we use the class name as data type in method declaration.
2. When we need to return an instance of a class from a method, we mention the class name as return type in the method declaration.

Consider, the following example.

There is a class Word having a variable word and a method display.

Display method is used to print the value in word.

Another class WordTest has a method append which takes Word object as argument, appends something to it and then returns the object.

Word.java

----------------------------

public class Word {
String word = "Monica";

public void display(){
    System.out.println("Word is : " + word);
}
}

WordTest.java

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public class WordTest {
public static Word append(Word w){
    w.word = "Hello " + w.word;
    return w;
}

public static void main(String[] args) {
     Word obj = new Word();
     obj.display();
     obj = append(obj);
     obj.display();
}

}

Output

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