Question

i want to extract number and add these numbers using Java and String remain same.

String as-

String msg="1,2,hello,world,3,4";

output should come like- 10,hello,world

Thanks

Answer 1

String[] parts = msg.split(",");
int sum = 0;
StringBuilder stringParts = new StringBuilder();
for (String part : parts) {
    try {
        sum += Integer.parseInt(part);
    } catch (NumberFormatException ex) {
        stringParts.append("," + part);
    }
}
stringParts.insert(0, String.valueOf(sum));

System.out.println(stringParts.toString()); // the final result

Note that the above practice of using exceptions as control flow should be avoided almost always. This concrete case is I believe an exception, because there is no method that verifies the “parsability” of the string. If there was Integer.isNumber(string), then that would be the way to go. Actually, you can create such an utility method. Check this question.