No “tryParseDouble” in Java? [duplicate]

Answer 1

The problem you have is that you have two possible outcomes. Either you have a valid double or you don't. If you have a return value you need to check for you might forget to check or you have an if check for every value.

try {
    double d = Double.parseDouble(input);
    double d2 = Double.parseDouble(input2);
    double d3 = Double.parseDouble(input3);
    double d4 = Double.parseDouble(input4);
    // all number are good.

} catch (NumberFormatException e) {
    e.printStackTrace(); //prints error
}

or

double d, d2, d3, d4;
if (tryParseDouble(input)) {
    d = parseDouble(input);

    if (tryParseDouble(input2)) {
        d2 = parseDouble(input2);

        if (tryParseDouble(input3)) {
            d3 = parseDouble(input3);

        } else {
            if (tryParseDouble(input4)) {
                d4 = parseDouble(input4);

            } else {
                System.out.println("Cannot parse " + input4);
            }

            System.out.println("Cannot parse " + input3);
        }

    } else {
        System.out.println("Cannot parse " + input2);
    }

} else {
    System.out.println("Cannot parse " + input);
}