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Nicklas Millard
9,542 PointsProblems with the code challenge...
Hi,
Can anyone see what I am doing wrong here?
public Map<String, Integer> getCategoryCounts() {
Map<String, Integer> categoriesMap = new HashMap<String, Integer>();
for (BlogPost blogpost : getPosts()) {
for (String category : blogpost.getCategory()) {
int count++;
categoriesMap(category, count);
}
}
return categoriesMap;
}
2 Answers
indraneel
2,211 PointsShould be something like this. Hope this helps.
import java.util.Map;
import java.util.HashMap;
public Map<String, Integer> getCategoryCounts() {
Map<String, Integer> categoriesMaps = new HashMap<String, Integer>();
for (BlogPost blogPost : mPosts) {
String category = blogPost.getCategory();
Integer count = categoriesMaps.get(category);
if (count == null) {
count = 0;
}
count++;
categoriesMaps.put(category, count);
}
return categoriesMaps;
}
Seth Kroger
56,413 PointsBy using int count++; you're creating a new count of zero every loop and incrementing, so the word count is always 1. What you should do is retrieve the count from the map first, make sure it's not null, then increment and store it back.
Nicklas Millard
9,542 PointsHi! Thanks for helping.
I've changed the code to this:
public Map<String, Integer> getCategoryCounts() {
Map<String, Integer> categoriesMap = new HashMap<String, Integer>();
for ( BlogPost blogPost : getPosts() ) {
for ( String category : blogPost.getCategory()) {
count++;
categoriesMap(category, count);
}
}
return categoriesMap;
}
But I get these errors:
./com/example/Blog.java:20: error: for-each not applicable to expression type for ( String category : blogPost.getCategory()) { ^ required: array or java.lang.Iterable found: String ./com/example/Blog.java:22: error: cannot find symbol categoriesMap(category, count); ^ symbol: method categoriesMap(String,int) location: class Blog Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 2 errors
Seth Kroger
56,413 PointsBlogPost.getCategory() returns a String not a Collection, so there is only one category per post. to the inner for loop is unnecessary.