Check if the number in string object is between range java 8

Question

I want to check if a number in string is in a given range or not. if yes then add 100 to the number present in the string and return string.

For example channel has id name and start and end time

 // created list of channel object   
List<Channel> cList= Arrays.asList(
    new Channel(1,"BBC","0300","0500"),
    new Channel(2,"TR","0400","0509"),
    new Channel(3,"NEWS","0700","0800")); 
/*logic to identifyif the value is in between given rabge and add 100 to it.*/
List<Channel> cNewList=cList.forEach(
     // perform operation to find if c.getstartTime() between 
    // range(100,500).then add 100 in it.
);
               

I know we can use Integer.parseInt(String) method to convert to integer value but I want the output back to a string.

Answer 1

You have to parse the string to integer to do the comparison, so you're good with the parseInt .

Afterwards can always concat your integers with an empty string to get back a string (eg 1 + "" will give you a string).

Answer 2

Assuming that you class Channel has these member fields:

class Channel {
    private int index;
    private String name;
    private String startTime;
    private String endTime;
...
}

and in the Main class you define a static helper method:

public class Main {

    private static Channel getNewStartTimeChannel(Channel c) {
        // parse the string to int
        int x = Integer.parseInt(c.getStartTime());
        if (x > 100 && x < 500) {
            return new Channel(
                    c.getIndex(),
                    c.getName(),
                    // update the int value of the startTime and transform it back to String
                    "" + (x + 100),
                    c.getEndTime());
        }
        return c;
    }

you can easily transform the Channels in the original list into the new one:

public static void main(String[] args) {
    List<Channel> cList = Arrays.asList(
            new Channel(1, "BBC", "0300", "0500"),
            new Channel(2, "TR", "0400", "0509"),
            new Channel(3, "NEWS", "0700", "0800")
    );
    List<Channel> cNewList = cList.stream()
                    .map(Main::getNewStartTimeChannel)
                    .collect(Collectors.toList());
}