尝试基于字符串arraylist的索引加总double array list的总成本

Question

So I have an array list of recurring strings deploy , and an array list of those strings with no duplicates singDeploy . I also have an array list of doubles rate that have the same index as deploy . I'm trying to add up all the rates for each deploy string and store them in totCost that match up to singDeploy index however my for loop is giving me an java.lang.IndexOutOfBoundsException . Not too sure why and still don't fully know if my loop gets that job done.

 List<String> deploy = new ArrayList<>();
 List<String> singDeploy = new ArrayList<>();
 List<Double> totCost = new ArrayList<>();
 List<Double> rate = new ArrayList<>();
  singDeploy.addAll(Arrays.asList("Green Cow", "Green Elephant", "Green Rhinocerous", "Purple Cow", "Yellow Cat", "Red Sloth"));

  deploy.addAll(Arrays.asList("Green Cow", "Green Cow", "Green Elephant", "Green Cow", "Green Cow", "Green Rhinocerous", "Purple Cow", "Yellow Cat", "Red Sloth", "Green Cow", "Purple Cow", "Green Cow", "Red Sloth", "Yellow Cat", "Green Rhinocerous", "Purple Cow"));

  rate.addAll(Arrays.asList(0.553683754016, 1.02150872447, 0.134625067987, 1.98664453833, 0.861269450714, 0.36946659851, 0.909230205525, 0.00248039618935, 0.160619970732, 0.545320579333, 0.0709241158945, 3.96782782573E-6, 0.849530002338, 1.29965105158, 6.72974424027E-6, 4.51463564725E-6));


 for(int i=0;i<singDeploy.size();i++) {
    for(int j=0;i<deploy.size();j++) {
    if(singDeploy.get(i)==deploy.get(j)) {
        double temp=totCost.get(i);
        System.out.println(temp);
        totCost.add(temp+=rate.get(j));
    }
     else {
        j++;
        }
   }

Answer 1

Multiple things,

for(int j=0;j <deploy.size();j++) { // Use j ,

totCost.get(j); // Use j again,

singDeploy.get(i).equals(deploy.get(j)) // Use equals

Or try this,

for(int i=0;i < singDeploy.size() ;i++) {
             Double curCost = 0.0;
             String currDeploy = singDeploy.get(i);
             for(int j=0;j<deploy.size();j++) {
                 if(deploy.get(j).equals(currDeploy))
                     curCost += rate.get(j);
             }
             totCost.add(curCost);
          }

Answer 2

In this line: double temp=totCost.get(i); You are trying to access an element in totCost which does not have an element inside. That could be the reason for IndexOutOfBound.

Answer 3

At line for(int j=0;i<deploy.size();j++) { , you should put j instead of i

for(int j=0;j<deploy.size();j++) {

It is going for infinite loop in your current code. Also, as Bhargav mentioned, you are trying to access the element ie

double temp=totCost.get(i);

which doesn't have any element inside.