从arraylist的总和中获取arraylist值的百分比

Question

i have an array list where i have some value arraylist like

ArrayList<Integer> keyList = new ArrayList<Integer>(treeMap.keySet());

Values here: *62,58,10,6* i am getting some if value *136.0*

Now what i want is to get % of each value and print them again as an arraylist there something like this

*40%,34%,16%, 10%*

Answer 1

double sum = 0.0; //if you use version earlier than java-8
//double sum = IntStream.of(keyList).sum(); //if you are using java-8 
for(int i = 0 ; i < keyList.size() ; i++){
  sum += keyList.get(i);    
}
for(int i = 0 ; i < keyList.size() ; i++){
  System.out.println((keyList.get(i)/sum )*100 + "%");
}

Answer 2

In java 8, you can do it like this:

    ArrayList<Integer> arrayList = new ArrayList<>(Arrays.asList(62, 58, 10, 6));
    double sum = arrayList.stream().mapToInt(Integer::intValue).sum();
    arrayList.stream().forEach(i -> System.out.printf("%.2f%% ", (i / sum) * 100));