我如何在Android中的不同ArrayList中存储不同的值

Question

I'm working with string value like this String result "aa,bb,cc,dd,ee" .

And already split it into aa bb cc dd ee with

qrList = result.getContents().toString().split("\\,");
List<String> resultToString= new ArrayList(Arrays.asList(qrList));

Then I create four ArrayLists.

 ArrayList<String> strA = new ArrayList();
 ArrayList<String> strB = new ArrayList();
 ArrayList<String> strCD = new ArrayList();
 ArrayList<String> strE = new ArrayList();

When I use this code below to store string into each new ArrayList .

for(int count=0; count<resultToString.size(); count++){
    //separate string to array list
    if(count%5==0){
        strA.add(resultToString.get(count));
    }else if(count%5==1){
        strB.add(resultToString.get(count));
    }else if(count%5==2||count%5==3){
        strCD.add(resultToString.get(count));
    }else if(count==4){
        strE.add(resultToString.get(count));
    }

The correct result would be

• strA stored aa
• strB stored bb
• strCD stored cc and dd
• strE stored ee

It doesn't work because I only get the index value at 0 (strA stored aa). What should I do to improve my code?

Answer 1

Simply use startsWith and add appropriate values to list

    for(int count=0; count<resultToString.size(); count++){
        //separate string to array list
        String s = resultToString.get(count);

        if(s.startsWith("a")){
            strA.add(s);
        }else if(s.startsWith("b")){
            strB.add(s);
        }else if(s.startsWith("c")||s.startsWith("d")){
            strCD.add(s);
        }else if(s.startsWith("e")){
            strE.add(s);
        }
    }

Answer 2

Modulus operator describes the remainder of your equation. Let us show and explain an example:

As explained in this documentation , performing modulus between two values will only show you the remainder value. For eg 8 % 3 == 2 because 8 divided by 3 leaves a remainder of 2.

The reason your code is not showing your desired results is due to the usage of your modulus operator. Regarding improving your code, I can tell that all you wanted is to use the Array List index so as to add the string from the resultToString Array List.

Therefore I would modify your loop in the following manner:

for(int count=0; count < resultToString.size(); count++) {
  //separate string to array list
  if (count == 0){
     strA.add(resultToString.get(count));
  } else if (count == 1){
     strB.add(resultToString.get(count));
  } else if (count == 2 || count == 3){
     strCD.add(resultToString.get(count));
  } else if (count == 4){
     strE.add(resultToString.get(count));
  }
}

An alternative is to loop directly on the resulting String[] and use that relative counter in the for loop for eg

String[] qrList = results.getContent().toString().split("\\,");

for(int count = 0; count < qrList.length; count++) {
  //each index represents the split string e.g
  // [0] == "aa"
  // [1] == "bb"
  // [2] == "cc"
  // [3] == "dd"
  // [4] == "ee"
  if (count == 0){
     strA.add(qrList[count]);
  } else if (count == 1){
     strB.add(qrList[count]);
  } else if (count == 2 || count == 3){
     strCD.add(qrList[count]);
  } else if (count == 4){
     strE.add(qrList[count]);
  }
}