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Start your free trialCasey Huckel
Courses Plus Student 4,257 PointsWhat's missing here?
Get 7 errors here and don't know why. I'll post compilation errors in addition to code.
package com.example;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class BlogPost implements Comparable<BlogPost>, Serializable {
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 int compareTo(BlogPost other) {
if (equals(other)) {
return 0;
}
return mCreationDate.compareTo(other.mCreationDate);
}
public String[] getWords() {
return mBody.split("\\s+");
}
public List<String> getExternalLinks() {
List<String> links = new ArrayList<String>();
for (String word : getWords()) {
if (word.startsWith("http")) {
links.add(word);
}
}
return links;
}
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;
}
}
package com.example;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import java.util.Map;
import java.util.HashMap;
import java.util.Date;
import java.util.HashSet;
public Map<String, Integer> getCategoryCounts() {
Map<String, Integer> counts = new HashMap<>();
for (BlogPost mPost : mPosts) {
String category = mPost.getCategory();
Integer count = counts.get(category);
if (count == null) count = 0;
count++;
counts.put(category, count)
}
return counts;
}
public class Blog {
List<BlogPost> mPosts;
public Blog(List<BlogPost> posts) {
mPosts = posts;
}
public List<BlogPost> getPosts() {
return mPosts;
}
public Set<String> getAllAuthors() {
Set<String> authors = new TreeSet<>();
for (BlogPost post: mPosts) {
authors.add(post.getAuthor());
}
return authors;
}
}
1 Answer
Grigorij Schleifer
10,365 PointsHi Casey,
delete the second imports of Map and HashMap.
Let us look at your code:
public Map<String, Integer> getCategoryCounts() {
Map<String, Integer> counts = new HashMap<>();
for (BlogPost mPost : mPosts) {
String category = mPost.getCategory();
Integer count = counts.get(category);
if (count == null) { // added a curly bracket to open the if loop
count = 0;
}
count++;
counts.put(category, count); // added a semicolon here
} // added a curly bracker to close the for loop
return counts;
}
You was incrementing count only if it is null, not for every time you encounter the category. And you added category + count if the count was null. So I moved
count++;
counts.put(category, count);
out of the if statement.
I hope it help you a little bit.
Grigorij
Jordan Ernst
5,121 Pointsdon't forget >>
Map<String, Integer> counts= new HashMap<String, Integer>();
Casey Huckel
Courses Plus Student 4,257 PointsCasey Huckel
Courses Plus Student 4,257 PointsHere's a list of errors:
./com/example/Blog.java:13: error: class, interface, or enum expected public Map getCategoryCounts() { ^ ./com/example/Blog.java:15: error: class, interface, or enum expected for (BlogPost mPost : mPosts) { ^ ./com/example/Blog.java:17: error: class, interface, or enum expected Integer count = counts.get(category); ^ ./com/example/Blog.java:18: error: class, interface, or enum expected if (count == null) count = 0; ^ ./com/example/Blog.java:19: error: class, interface, or enum expected count++; ^ ./com/example/Blog.java:20: error: class, interface, or enum expected counts.put(category, count) ^ ./com/example/Blog.java:23: error: class, interface, or enum expected } ^ Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 7 errors