Query:function of method toString()?

[Jack Dowson]

Hello Everyone:
I came across a demo yesterday,which use System.out.println(cla) to
print a sentence on screen.But "cla" here is a class name.There is only
one method in this class definede asublic String toString().
Here is my question:If a mehod like "public String to String()" defined
in a class,then the class name will represent a string in a String
context,right?

Any help will be greatly appreciated!
Dowson.

 

[Patricia Shanahan]

Hello Everyone:
I came across a demo yesterday,which use System.out.println(cla) to
print a sentence on screen.But "cla" here is a class name.There is only
one method in this class definede asublic String toString().
Here is my question:If a mehod like "public String to String()" defined
in a class,then the class name will represent a string in a String
context,right?

Any help will be greatly appreciated!
Dowson.

Java does not have a concept of "X context".

PrintStream has several println methods, including one that takes an
Object argument. If cla is a reference to some object,
System.out.println(cla) prints the result of that object's toString
method. That happens regardless of what other methods the class has.

EVERY object has a public String toString() method, either declared or
inherited, because Object declares public String toString().

However, I am not sure what you mean by '"cla" is a class name. The
following program, with a class name as println argument, does not
compile because of a syntax error:

public class MyClass {
public static void main(String[] args){
System.out.println(MyClass);
}
}

You can call println for the Class object associated with a class:

System.out.println(MyClass.class)

That prints the result of the toString method for the Class object for
MyClass, the word "class" followed by a space and the name of the class.

Note: Watch the capitalization. "class" means the general concept of a
class. "Class" means the class of the object the

Patricia

 

[Jack Dowson]

Thank you so much,Patricia Shanahan!!!

Dowson.