Check if weekday is in the past DateTime c# -


i working on weather application , want when user input "tuesday" , present day wednesday, give me weather of coming tuesday instead.

any please?

there many ways "next tuesday" exact solution depends on answer question:

if today tuesday, , user types in tuesday, want today, or next week?

if answer "today", following 2 solutions work:

public static datetime nextdatebydayofweek1(dayofweek dow) {     var daysuntil = ((dow - datetime.today.dayofweek) + 7) % 7;     return datetime.today.adddays(daysuntil); }  public static datetime nextdatebydayofweek2(dayofweek dow) {     var date = datetime.today;     while (date.dayofweek != dow)         date = date.adddays(1);     return date; }

if answer "next week", should add 1 day date use in methods:

public static datetime nextdatebydayofweek1(dayofweek dow) {     var daysuntil = ((dow - datetime.today.adddays(1).dayofweek) + 7) % 7;     return datetime.today.adddays(1 + daysuntil); }  public static datetime nextdatebydayofweek2(dayofweek dow) {     var date = datetime.today.adddays(1);     while (date.dayofweek != dow)         date = date.adddays(1);     return date; }

you can generalize them:

public static datetime nextdatebydayofweek1(datetime startdate, dayofweek dow) {     var daysuntil = ((dow - startdate.dayofweek) + 7) % 7;     return startdate.adddays(daysuntil); }  public static datetime nextdatebydayofweek2(datetime startdate, dayofweek dow) {     var date = startdate;     while (date.dayofweek != dow)         date = date.adddays(1);     return date; }

the startdate returned if of correct day of week. "next week's date", use datetime.today.adddays(1) when calling it, otherwise use datetime.today.

why 2 solutions?

because "worst case scenario" loop-based solution 6 iterations, whereas 1 using remainder operator might need documentation understood people reads code. pros , cons.


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