string - How to write Java code to take any date user inputs, and list the next 40 days? -

-

i trying ensure nextday method can add 1 day date user entered , ensure adds 40 days correctly, taking account correct days per month , leap years

public nextday() {     (int count = 1; count < 40; count++)         ; }  public string todaydatestring() // todaydatestring method {     int countdays = 0;      (int = 1; < getmonth(); i++) {         if (i == 2 && checkleapyr(getyear()))             countdays += 29;         else             countdays += dayspermonth[i];     }     countdays += date;     string message = string.format("\n", countdays, getyear());     return message; }  private boolean checkleapyr(int inyear) { // check leap year method.     if (getyear() % 400 == 0 || (getyear() % 4 == 0 && getyear() % 100 != 0))         return true;     else         return false; }

below menu supposed allow user choose enter date or quit, date not being accepted correctly.

{  public static void main ( string [] args) // user selects how enter dates  {          +"(1) enter date mm/dd/yyyy\n"    +"(any key) quit\n";   int input=0;    date newdate;    do{    string userinput = joptionpane.showinputdialog(null, menu);    input = integer.parseint( userinput);    string outputmessage="";     if ( input = 1)    {     userinput =joptionpane.showinputdialog(null, "please enter date 02/28/2011");      switch ( input )  // here menu choice evaluated     {      case 1 :       token = userinput.split("/");       if (token.length == 3 )        {        newdate = new date( integer.parseint( token[0]),         integer.parseint( token[1]), integer.parseint( token[2]) );        outputmessage = newdate.tostring();        joptionpane.showmessagedialog(null, outputmessage);       }        break;       case 2:   } while ( input <>1); // quit program when user selects key other 1 @ menu.

  • you should use java.text.dateformat parse date strings
  • writing own date arithmetic error prone (leap years 1 exception among many), better use java.util.calendar implementation instead.

as date arithmetic, here's how it's done calendar:

//todo: parse input string dateformat date startdate = ... // parsed date  calendar cal = new gregoriancalendar(); cal.settime(startdate);  (int = 0; < 40; i++) {      // add day     cal.add(calendar.date, 1);      // , new result date     date date = cal.gettime();      system.out.println(date); }

if need count backwards, add negative time amounts (days, hours etc).


Comments

Post a Comment

Popular posts from this blog

c# - How Configure Devart dotConnect for SQLite Code First? -

-
can configure following sample code ? when run following code, error : no entity framework provider found ado.net provider invariant name 'devart.data.sqlite' setting in machine.config <system.data> <dbproviderfactories> <add name="dotconnect sqlite" invariant="devart.data.sqlite" description="devart dotconnect sqlite" type="devart.data.sqlite.sqliteproviderfactory, devart.data.sqlite, version=4.6.287.0, culture=neutral, publickeytoken=09af7300eec23701" /> </dbproviderfactories> </system.data> after add below block code in app.config <?xml version="1.0"?> <configuration>   <configsections> <!-- more information on entity framework configuration, visit http://go.microsoft.com/fwlink/?linkid=237468 --> <section name="entityframework" type="system.data.entity.internal.configfile.entityframeworksection, entit...
Read more

java - Copying object fields -

-
what best way of copying classes when need have 2 independent variables? have simple class: public class myclass { boolean = false; string b= "not empty"; } do need make method : assign(myclass data ) { a= data.a; b= data.b; } is there automatic method copy (duplicate) objects in java? do need make method : pretty close. instead of making method, should make constructor. such constructors called copy constructor , , create them this: myclass(myclass data) { = data.a; b = data.b; } and create copy of instance, use constructor this: myclass obj1 = new myclass(); myclass obj2 = new myclass(obj1); copy constructor can tedious : using copy constructor create deep-copy can tedious, when class has mutable fields. in case, assignment create copy of reference, , not object itself. have create copy of fields (if want deep copy). can go recursive. a better way create deep copy serialize , deserialize object. why not use clone()? ...
Read more

c++ - Clear the memory after returning a vector in a function -

-
i have function processes , stores lot of data in , returns results vector of class. amount of data stored in function tremendous , want clear storage memory of function after finished job. necessary (does function automatically clear memory) or should clear memory function? update: vector<customers> process(char* const *filename, vector<int> id) { vector<customers> list_of_customers; (perform actions) return list_of_customers; } variables defined locally within function automatically released @ end of function scope. destructors objects called, should free memory allocated objects (if objects coded correctly). example of such object std::vector . anything you've allocated new must have corresponding delete release storage. try avoid doing own allocation , use raii instead, i.e. containers or smart pointers.
Read more