CODEWITHSUNDEEP
flutterdart
rameez khan
rameez khan

Reputation: 359

Flutter compare two time string

I have 2 String in which I have hours and min

String1  = 2 HOUR 0 MIN
String2  = 1 HOUR 30 MIN

I need to check if I subtract String2 time with String1 values to go to negative or not.

For example, if I subtract String2 with String1 value will be in a time like 00:30

So basically I just need to check String2 is not greater then String1, I am badly stuck on this how can i check it

Upvotes: 0

Views: 208

Answers (2)

Lulupointu
Lulupointu

Reputation: 3584

I would consider first converting the Strings to Duration by parsing them. This can be done with a regexp for example:

/// Returns the duration associated with a string of
/// the form "XX HOUR XX MIN" where XX can be 1 or 2 digits
///
/// TODO: add check for fail safe
Duration _parseDateString(String dateString) {
  // Make sure that this is correct, it really depends on the form of your input string
  final dateStringRegexp = RegExp(r'(\d*) HOUR (\d*) MIN');

  final match = dateStringRegexp.firstMatch(dateString);
  final hours = int.parse(match!.group(1)!);
  final minutes = int.parse(match.group(2)!);

  return Duration(hours: hours, minutes: minutes);
}

Once you have this, it's pretty easy to compare the times:

final dateString1 = "2 HOUR 0 MIN";
final dateString2 = "1 HOUR 30 MIN ";

final duration1 = _parseDateString(dateString1);
final duration2 = _parseDateString(dateString2);

print(duration1.compareTo(duration2));

Upvotes: 0

Code on the Rocks
Code on the Rocks

Reputation: 17634

Is there a reason you're using Strings instead of Durations? The duration class has built in methods to add and subtract hours, mins, etc.

If you have to use strings, I would first convert them to Durations and add/subtract them.

Upvotes: 1

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