CODEWITHSUNDEEP
javastringint
Oria Gruber
Oria Gruber

Reputation: 1533

How to extract two integers from unknown indexes from a string

Very simple question - I have a string that looks like PR:MTH 1 MTR 7. I want to extract the numbers in that string to integer variables.

The problem is that I don't know how many digits these integers have. for example PR:MTH 100000 MTR 777 is also a valid string. So I can't specify the exact indexes where the numbers are.

All we can say for sure is that the MSB of the first number is at index 7 (I counted).

Is there some String method or StringBuilder method in java that does this? or do I need to write one of my own?

Upvotes: 0

Views: 102

Answers (4)

Bohemian
Bohemian

Reputation: 425198

To solve the general case, use regex to find the numbers:

String number1 = str.replaceAll("\\D*(\\d+).*", "$1");
String number2 = str.replaceAll("\\D*\\d+\\D+(\\d+).*", "$1");

This has the advantage of working with input that doesn't have a clear delimiter, eg if the input string was

foo123bar456baz

the above code would successfully extract 123 and 456.

Upvotes: 0

Yassin Hajaj
Yassin Hajaj

Reputation: 21995

String#split is your friend in this situation

Split the string with spaces and colons and parse the corresponding indexes.

String s = "PR:MTH 100000 MTR 777";
String[] split = s.split("[ :]");
int one = Integer.parseInt(split[2]);
int two = Integer.parseInt(split[4]);

Upvotes: 3

Xavier Silva
Xavier Silva

Reputation: 267

You can do yourString.split(" "); and iterate that array searching for all the numbers, using a try-catch block. In order to save them, you can use an ArrayList<Integer>.

I would do something like:

    String myString = "dsfsd 12 12 dd";
    ArrayList<Integer> numbers = new ArrayList<>();

    String[] splitString = myString.split(" ");

    for (String split : splitString) {
        try {
            numbers.add(Integer.valueOf(split));
        } catch (java.lang.NumberFormatException e) {
            //not a number
        }
    }

    System.out.printf("I have %d numbers in my String! \n", numbers.size());

In order to obtain the numbers, you just need to iterate the ArrayList. 

    for (Integer number : numbers) {
        //your code
        System.out.println(number);
    }

Hope this helps you!

Upvotes: 1

user3676194
user3676194

Reputation: 86

you should try split(" ") and then take values u need and convert to integer

Upvotes: 1

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