The Object and Objects Classes - Beginning Java 8 Fundamentals - page 290

// Print the string representations
System.out.println(objStr);
System.out.println(intHolderStr);
java.lang.Object@360be0
com.jdojo.object.IntHolder@45a877
Note that your IntHolder class does not have a toString() method. Still, you were able to call the toString()
method using the intHolder reference variable because all methods in the Object class are available in all classes
automatically.
You may notice that the string representation that is returned from toString() method for IntHolder object is
not so useful. It does not give you any clues about the state of the IntHolder object. Let's reimplement the toString()
method in your IntHolder class. You will call the new class SmartIntHolder . What should your toString() method
return? An object of SmartIntHolder represents an integer value. It would be fine just to return the stored integer
value as a string. You can convert an integer value, say 123 , into a String object using the valueOf() static method
of the String class as
String str = String.valueOf(123); // str contains "123" as a string
Listing 7-5 has the complete code for your SmartIntHolder class.
Listing 7-5. Reimplementing toString() Method of the Object Class in the SmartIntHolder Class
// SmartIntHolder.java
package com.jdojo.object;
public class SmartIntHolder {
private int value;
public SmartIntHolder(int value) {
this.value = value;
}
public void setValue(int value) {
this.value = value;
}
public int getValue() {
return value;
}
/* Reimplement toString() method of the Object class */
public String toString() {
// Return the stored value as a string
String str = String.valueOf(this.value);
return str;
}
}