Bubble sort arraylist

Question

I have an array of objects read in from a user into an arraylist, when I attempt to bubble sort this data based off of a String parameter the program experiences a runtime error and the code does not execute.

Resort temp;
    while (finished = true) {
        finished = false;
        for (int index = 0; index < numResorts - 1; index++) {
            String nam1 = resorts.get(index).getName();
            String nam2 = resorts.get(index + 1).getName();
            if (nam1.compareTo(nam2) > 0) {
                temp = resorts.get(index);
                resorts.set(index, resorts.get(index + 1));
                resorts.set(index + 1, temp);
                //resorts.get(index) = resorts.get(index + 1);
                //resorts.get(index + 1) = temp;
                finished = true;
            }
        }
    }

Rohit Jain · Accepted Answer · 2013-09-23 20:43:02Z

3

You notice that you have an infinite loop there? The following while loop:

while (finished = true)

... always execute infinitely, since the expression always evaluate to true, because of that assignment. This is the reason why you should not compare boolean values. Simply do:

while (finished)  // this is enough.

answered Sep 23, 2013 at 20:43

Rohit Jain

214k45 gold badges419 silver badges534 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Chandan Patra · Accepted Answer · 2014-03-05 19:24:44Z

0

Here is my solution:

List<Integer> sortedlists = new ArrayList<Integer>();
public List<Integer> sortBs(List<Integer> al) {
    sortedlists = al;
    for(Integer out = al.size()-1; out>1; out--) {
        for(Integer i = 0; i < out;i ++){
            int n = i+1;
            if(sortedlists.get(i) > sortedlists.get(n)) {
                Integer temp = sortedlists.get(i);
                sortedlists.set(i, sortedlists.get(n));
                sortedlists.set(n, temp);
            }
        }
    }

    return sortedlists;
}

answered Mar 5, 2014 at 19:24

Chandan Patra

4912 gold badges9 silver badges19 bronze badges

Collectives™ on Stack Overflow

Bubble sort arraylist

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related