First you split the string into an array:
String str = "1.2, 3.1, 5.3, 4.5";
String[] arrOfStr = str.split(",");
Then you loop through the array and convert to floats:
import java.util.ArrayList;
ArrayList <Double> volts = new ArrayList<Double>();
for (int i = 0; i < arrOfStr.length; i++) {
volts.add(Double.parseDouble(arrOfStr[i]));
}
System.out.println(volts);
4
solved How to convert a String to a float array?