How concatenate a LinkedList in Java?

Question

I have a LinkedList:

Linkedlist<String> m = new Linkedlist<String>();

and it contains:

m = {"apple", "banana", "pineapple", "orange", "mango"};

My current code is:

string s = "";
for(int i = 0; i < m.size(); i++)
{
 s += a.get(i);
 s += a.get(i);
 s += a.get(i);
 return s;
}

What I expect:

[apple] or [banana, orange] or [apple, pineapple, mango].

But my result is always:

[apple, apple, apple]

What must I do to get the expected output?

• Pbd: what exactly is the question?
• Crazymango: Thanks, pbd , this is my first time to ask question. I just want to know how to use loop to loop over the linked list and use compound additive operator to show the result I wanted.
• Bernhard Barker: @Pbd OP probably meant LinkedList, and this is probably Java, but you should probably ask first before editing the question like that without being sure. Editing a post to change class names is something one should almost never do.
• Crazymango: @Dukeling, sorry about my mistake. It is a java question.
• Bernhard Barker: If you get [apple, apple, apple] with a foreach loop, my guess is that the linked-list contains only apple 3 times, or you just took the first element each time. You might want to construct and post a Minimal, Complete, and Verifiable example that shows the problem you're having.

Answer 1

You can output List in different ways.

1) First is closest to your code

LinkedList<String> m = new LinkedList<String>();
m.add("apple");
m.add("banana");
m.add("pineapple");
m.add("orange");
m.add("mango");
StringBuilder s = new StringBuilder();
for(String value : m)
 s.append(value);
System.out.println(s);

Output is (perhaps you would like to format it a bit)

applebananapineappleorangemango

2) Easiest way, in my opinion, is to connect StringUtils from apache.

System.out.println(StringUtils.join(m, ", "));

Output

apple, banana, pineapple, orange, mango

3) If you need it just for debug, you can simple use toString() from list. So

System.out.println(m.toString());

gives you

[apple, banana, pineapple, orange, mango]