String « collection « Java Collection Q&A

1. How to lowercase every element of a collection efficiently?    stackoverflow.com

Whats the most efficient way to lower case every element of a list or set? My idea for a List:

final List<String> strings = new ArrayList<String>();
strings.add("HELLO");
strings.add("WORLD");

for(int i=0,l=strings.size();i<l;++i)
{
  strings.add(strings.remove(0).toLowerCase());
}

2. Why is Collection.class Illegal?    stackoverflow.com

I am puzzled by generics. You can declare a field like:

Class<Collection<String>> clazz = ...

Class<Collection<String>> clazz = Collection<String>.class;

  ...

3. Collection    stackoverflow.com

Whats the main difference between a Collection of String (Collection)and a simple, plain collection?

4. Preferred Idiom for Joining a Collection of Strings in Java    stackoverflow.com

Given a Collection of Strings, how would you join them in plain Java, without using an external Library? Given these variables:

Collection<String> data = Arrays.asList("Snap", "Crackle", "Pop");
String separator = ", ";
String joined; // ...

5. what is the java correponding collection to Dictionary    stackoverflow.com

coming from .Net world, just want to know what is the corresponding collection to .Net Dictionary

6. How to make a Collection object from comma seperated values    stackoverflow.com

I have a string object like

            final String demoString = "1,2,19,12";

7. Java: Enumeration from set    stackoverflow.com

I have a simple collections question. I have a Set<String> object. I want an enumeration of the strings in that set. What is the cleanest/best way to go about it?

8. Counting vowles in a collection of String objects    java-forums.org

I am working on an exercise in Thinking in java 4th edition, I have an idea of how to do it, but I am not sure how to do it the way the book specifies. the question is: Create a set of vowels. working from uniquewords.java, count and display the number of vowels in each input word and also display the ...

9. how to create a collection which allows String and myobjects only using gen    forums.oracle.com

I once saw in our codebase someone use a trick that did indeed allow him to put String and some other arbitrary type in the one collection. I won't post the code, because I strongly agree with the people saying it shouldn't be done, and also the instance where I saw it caused a very peculiar bug at a most inopportune ...