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Start your free trialSara Pasinato
1,023 PointsI don't understand the error in this program
the error is: ./com/example/Blog.java:32: error: for-each not applicable to expression type for(String c : post.getCategory() ){ ^ required: array or java.lang.Iterable found: String Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.
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;
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;
}
public Map<String, Integer> getCategoryCounts() {
Map<String, Integer> categoryCounts = new HashMap<String, Integer>();
for (BlogPost post : mPosts) {
for(String c : post.getCategory() ){
Integer count = categoryCounts.get(c);
if ( count == null){
count = 0;
}
count++;
categoryCounts.put(c,count);
}
return categoryCounts;
}
}
}
3 Answers
Alexander Vishnyakov
8,620 PointsForeach loop takes Collection as a parameter and then iterates through passed Collection. However you are trying to pass a String --> for(String c : post.getCategory() ). post.getCategory() --> returns String. In your case you don't need Foreach loop you can just write --> String c = post.getCategory();
Sara Pasinato
1,023 Pointsthanks ? Thanks for you support
Alexander Vishnyakov
8,620 PointsYou are welcome :)