Hi I need help with AddNums in Java

Question

write a function named addNums that takes a string parameter containing a colon-delimited list of 2-digit numbers(ex. 12:21:14), multiplies together the two digits in each number, and computes the sum of all of the resulting numbers. for example, AddNums(12:23:54") should return (1 * 2) + (2 * 3) + (5 * 4) = 28. Define any variables that you use.

Answer 1

public class AddNumsApp {

public static void main(String[] args) {

System.out.println(addNums("12:23:54"));

// Result: 28

}

// I assume expr is in VALID format

public static int addNums(String expr) {

// Parse each 2-digit number in the expr

String[] numbers = expr.split(":");

// numbers = [ "12", "23", "54" ]

// Result

int total = 0;

// Go over all numbers

for (String number : numbers) {

// Example:

// number: "23"

// number.charAt(0) -> return char '2'

// number.charAt(1) -> return char '3'

// number.charAt(0) - '0': Convert char '2' to number 2

// number.charAt(1) - '0': Convert char '3' to number 3

total += (number.charAt(0) - '0') * (number.charAt(1) - '0');

}

return total;

}

}