Java - Split String by Number and Letters

Question

So I have, for example, a string such as this C3H20IO

What I wanna do is split this string so I get the following:

Array1 = {C,H,I,O}
Ar         


        

Answer 1

An approach without REGEX and data stored using ArrayList:

String s = "C3H20IO";

char Chem = '-';
String val = "";
boolean isFisrt = true;
List<Character> chemList = new ArrayList<Character>();
List<Integer> weightList = new ArrayList<Integer>();
for (char c : s.toCharArray()) {
    if (Character.isLetter(c)) {
        if (!isFisrt) {
            chemList.add(Chem);
            weightList.add(Integer.valueOf(val.equals("") ? "1" : val));
            val = "";
        }
        Chem = c;
    } else if (Character.isDigit(c)) {
        val += c;
    } 
    isFisrt = false;
}
chemList.add(Chem);
weightList.add(Integer.valueOf(val.equals("") ? "1" : val));

System.out.println(chemList);
System.out.println(weightList);

OUTPUT:

[C, H, I, O]
[3, 20, 1, 1]

Answer 2

make (for loop) with size of input length and add following condition

if(i==number)
// add it to the number array

if(i==character)
//add it into character array

Answer 3

I did this as following

ArrayList<Integer> integerCharacters = new ArrayList();
ArrayList<String> stringCharacters = new ArrayList<>();

String value = "C3H20IO"; //Your value 
String[] strSplitted = value.split("(?<=\\D)(?=\\d)|(?<=\\d)(?=\\D)"); //Split numeric and strings

for(int i=0; i<strSplitted.length; i++){

    if (Character.isLetter(strSplitted[i].charAt(0))){
        stringCharacters.add(strSplitted[i]); //If string then add to strings array
    }
    else{
        integerCharacters.add(Integer.parseInt(strSplitted[i])); //else add to integer array
    }
}

Answer 4

You can use two patterns :

• [0-9]
• [a-zA-Z]

Split twice by each of them.

List<String> letters = Arrays.asList(test.split("[0-9]"));
List<String> numbers = Arrays.asList(test.split("[a-zA-Z]"))
            .stream()
            .filter(s -> !s.equals(""))
            .collect(Collectors.toList());

if(letters.size() != numbers.size()){
        numbers.add("1");
    }