Converting time Error Java

Question

Hello!
I've been trying to convert AM and PM.
An input would be something like "3:00 PM" and would output "15:00". It seems to work well until i input smth like "3:03 PM" which results in outputting "15:015". I immediately knew that i was replacing all in the string that has "3" with "15". But i don't know how to specifically replace only the hour "3" with 15 but not the minute. In other words, how can i replace a string of a specific index?

Answer 1

You should also check if the original time is AM or PM. You should not increase the hours when its morning.
Also the hours can be 1 digit or 2 digits. So substring is not very reliable.

I think the easiest way is to split the original string in multiple parts, something like this :

String time = "3:03 PM";
String[] parts = time.split(" ");
String[] hourMinute = parts[0].split(":");
System.out.println(hourMinute[0]);
System.out.println(hourMinute[1]);
System.out.println(parts[1]);

Then you can do your checks and changes, finally combine them again. I leave that part to you ;)

Answer 2

You are right, its in that line. The issue is, that you are replacing all 3s with 15.

You could simply use substring again to cut off the hours:
String lt = ft + time.substring(1);

Just as a hint:
When you go on with your code you should consider, that "12:00 PM" will not give you a correct result. Also AM inputs won't deliver correct results.

Answer 3

Here is the code.
time would be the input.
String ht = time.substring(0,1);
int newht = Integer.parseInt(ht);
newht = newht + 12;
String ft = Integer.toString(newht);
String lt = time.replace(ht,ft);
String fft = lt.replaceAll("PM", " ");
System.out.print(fft.trim());

I know that the error is in this line
String lt = time.replace(ht,ft); but i don't know how to fix it.

Answer 4

Thank You all! I followed your methods and it works now!!