Thread: how can count

how can i count in example the numbers of 1's in 101e
the answer should be 2

public class Main {
 
    public static void main(String[] args) {
        String string1 = "10010101010101";
        int sum = 0;
 
 
        for (int index = 0; index < string1.length(); index++) {
 
            char aChar = string1.charAt(index);
 
            if (aChar == '1') {
                sum =sum +1;
            }
        }
        System.out.println(sum);
    }
 
 
}

You define your string of choice, named string1, you define a counter sum, and then you parse your string character by character and compare it to 1. If 1st character is = 1, then sum =1 else sum = 0, if second character is =1 you add one to sum, or else zero, and you keep doing that inside a for loop, until you reach the end of your string (in other words the last character, whos posistion is equal to strings length).[COLOR="Silver"]

think you