How to Correctly Implement and Call the toString() Method in Java?

Addressing toString() Implementation in Java

In Java, the toString() method allows you to define a custom representation of an object as a string. Its default implementation provides class and identity information, but it can be overridden for a tailored output.

Proper toString() Override

Your Kid class attempts to use a constructor in the toString() method, which is incorrect. toString() should return a string representation, not create a new object.

To fix your code, return a string containing the object's data. For example:

public String toString() {
    return "Name: '" + this.name + "', Height: '" + this.height + "', Birthday: '" + this.bDay + "'";
}

Alternatively, you can use your IDE's code generation features to automatically create a toString() method. For instance, in Eclipse, right-click on the code and select Source > Generate toString.

Troubleshooting Constructor Call

The constructor in your Kid class has the wrong syntax:

public Kid (String n, double h, String date) {
      // method that toString() can't find somehow
      StringTokenizer st = new StringTokenizer(date, "/", true);
      n = this.name;
      h = this.height;
   }

The correct syntax for a constructor is:

public Kid (String name, double height, String date) {
    this.name = name;
    this.height = height;
    // Parse date here
}

Calling toString()

The code in your Driver class correctly calls the toString() method on kid1 and prints its result:

System.out.println(kid1.toString());

This will output the customized string representation of the Kid object, as specified in the toString() method.

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