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Java Java Data Structures - Retired Getting There Type Casting

Kumar Swamy
Kumar Swamy
149 Points
Posted by Kumar Swamy
Kumar Swamy
149 Points

Getting error for checking instance. TypeCastChecker.java:15: error: not a statement obj instanceof String;

To ckeck if object obj is an instance of string

com/example/BlogPost.java 
package com.example;

import java.util.Date;

public class BlogPost {
    private String mAuthor;
    private String mTitle;
    private String mBody;
    private String mCategory;
    private Date mCreationDate;

    public BlogPost(String author, String title, String body, String category, Date creationDate) {
      mAuthor = author;
      mTitle = title;
      mBody = body;
      mCategory = category;
      mCreationDate = creationDate;
    }

    public String getAuthor() {
      return mAuthor;
    }

    public String getTitle() {
      return mTitle;
    }

    public String getBody() {
      return mBody;
    }

    public String getCategory() {
      return mCategory;
    }

    public Date getCreationDate() {
      return mCreationDate;
    }
}
TypeCastChecker.java 
import com.example.BlogPost;
import java.lang.Object;

public class TypeCastChecker {
  /***************
  I have provided 2 hints for this challenge.
  Change `false` to `true` in one line below, then click the "Check work" button to see the hint.
  NOTE: You must set all the hints to false to complete the exercise.
  ****************/
  public static boolean HINT_1_ENABLED = false;
  public static boolean HINT_2_ENABLED = false;

  public static String getTitleFromObject(Object obj) {
    // Fix this result variable to be the correct string.
  obj instanceof String;
    String result = (String)obj;    
    return result;
  }
}

1 Answer

Kevin Faust
Kevin Faust
15,353 Points
Kevin Faust
Kevin Faust
15,353 Points

hi, you dont want to delete the prewritten code inside the getTitleFromObject method.

overall, you have the right idea down but checking if obj is an instance of a String should be within a if statement. i added a few comments on the solution below

  public static String getTitleFromObject(Object obj) {

    String result = ""; //prewritten code
    if (obj instanceof String) { //if obj is a string
     result = (String) obj; //type cast it and store it in the "result" variable
    }
    return result; //prewritten code. returns the "result" variable
  }