Java-使用indexOf方法作为输入

Question

So, I am trying to find a specific character within an input given by the user. In this problem, the user inputs a British telephone number using the format

(XXXX) XXX XXXX or (XXXXX) XXX XXX

where the area code is formed by the numbers within brackets, and the personal phone number is formed by the numbers after that.

Heretofore, I have tried - unsuccessfully - to use the indexOf(String) method to find the closing bracket within the user's input, with this being my code:

import javax.swing.JOptionPane;

public class L2ExerciseE {
    public static void main(String[] args) {
        String number = JOptionPane.showInputDialog("Please input thy number: ");

        String areaCode = number.substring(1, indexOf(")"));
        String telephoneNumber = number.substring((indexOf(")") + 1), 15);
        System.out.println();

        System.out.println("The area code is: " + areaCode);
        System.out.println("The telephone number: " + telephoneNumber);
    }
}

I guess that this problem is occurring because java uses a compiler, while Python , my previous language, used an interpreter, and, even though I've tried reading other answers, I'm having serious trouble understanding them.

What can I do to make my code work without over complicationg things? For the moment, we have only seen some I/O commands, arithmetic commands, basic concatenation, and some few other commands like .substring() , .indexOf() , and .trim() .

Thank you very much in advance!

Answer 1

indexOf() is not a stand-alone function (nothing in Java is a stand-alone function), it is a method on a String . You need to use number.indexOf(")") - you're looking for ")" in number .

Answer 2

Try below. Documentation of string class https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#substring(int)

String areaCode = name.substring(name.indexOf("(")+1,name.indexOf(")"));
        String personalNo = name.substring(name.indexOf(")")+1);

Answer 3

Use a regex pattern:

String number = "(1234) 123 1234";
String pattern = "\\((\\d{4})\\) (\\d{3} \\d{4})|\\((\\d{5})\\) (\\d{3} \\d{3})";
Pattern r = Pattern.compile(pattern);
Matcher m = r.matcher(number);
if (m.find()) { 
    System.out.println("Found area code: " + m.group(1));
    System.out.println("Found personal number: " + m.group(2));
}

The reason that a regex based solution might be the way to go here is that your exact number pattern may have some variety to it. For example, a number with more than one space might still be considered valid, and this is easy to expresss in a regex.

Demo

Answer 4

There is one mistake in your code. Try this: String areaCode = number.substring(1, number.indexOf(")")); String telephoneNumber = number.substring((number.indexOf(")") + 1), 15);