Date function problem
in [JavaScript]
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From: bruce on 27 Apr 2010 23:11 The input for this this code is YearT=2010, MonthIndex=3, DayT = 27, Start_HourT = 22, Start_MinutesT=15, End_HourT = 20, End_MinutesT = 15 var InputStart = new Date(); var InputEnd = new Date(); InputStart = Date(YearT, MonthIndex, DayT, Start_HourT,Start_MinutesT, 0,0); InputEnd = Date(YearT, MonthIndex, DayT, End_HourT, End_MinutesT,0,0); alert(Start_HourT + ":" + End_HourT); // output is 22:20 Correct output alert("==: " + (InputStart == InputEnd)); // Output is true?? Output Not Correct How am I "Misusing" JavaScript??? Thanks....
From: Stefan Weiss on 28 Apr 2010 02:52 On 28/04/10 05:11, bruce wrote: > The input for this this code is YearT=2010, MonthIndex=3, DayT = 27, > Start_HourT = 22, Start_MinutesT=15, > End_HourT = 20, End_MinutesT = 15 > > var InputStart = new Date(); > var InputEnd = new Date(); > > InputStart = Date(YearT, MonthIndex, DayT, Start_HourT,Start_MinutesT, > 0,0); > InputEnd = Date(YearT, MonthIndex, DayT, End_HourT, End_MinutesT,0,0); > > alert(Start_HourT + ":" + End_HourT); // output is 22:20 Correct > output > > alert("==: " + (InputStart == InputEnd)); // Output is true?? Output > Not Correct If you want to call Date as a constructor, you need to write var InputStart = new Date(...); // note the 'new' operator Without 'new', Date() will ignore its arguments and return a string representing the current date/time instead of a Date object. -- stefan
From: bruce on 28 Apr 2010 08:35 On Apr 28, 2:52 am, Stefan Weiss <krewech...(a)gmail.com> wrote: > On 28/04/10 05:11, bruce wrote: > > > > > The input for this this code is YearT=2010, MonthIndex=3, DayT = 27, > > Start_HourT = 22, Start_MinutesT=15, > > End_HourT = 20, End_MinutesT = 15 > > > var InputStart = new Date(); > > var InputEnd = new Date(); > > > InputStart = Date(YearT, MonthIndex, DayT, Start_HourT,Start_MinutesT, > > 0,0); > > InputEnd = Date(YearT, MonthIndex, DayT, End_HourT, End_MinutesT,0,0); > > > alert(Start_HourT + ":" + End_HourT); // output is 22:20 Correct > > output > > > alert("==: " + (InputStart == InputEnd)); // Output is true?? Output > > Not Correct > > If you want to call Date as a constructor, you need to write > > var InputStart = new Date(...); // note the 'new' operator > > Without 'new', Date() will ignore its arguments and return a string > representing the current date/time instead of a Date object. > > -- > stefan Thank you. That fixed my problem with the Date constructor. What am I doing wrong here??? Thank you.. Bruce
From: johncoltrane on 28 Apr 2010 09:22 Le 28/04/10 14:35, bruce a �crit : > On Apr 28, 2:52 am, Stefan Weiss<krewech...(a)gmail.com> wrote: >> On 28/04/10 05:11, bruce wrote: >> >> >> >>> The input for this this code is YearT=2010, MonthIndex=3, DayT = 27, >>> Start_HourT = 22, Start_MinutesT=15, >>> End_HourT = 20, End_MinutesT = 15 >> >>> var InputStart = new Date(); >>> var InputEnd = new Date(); Here InputStart and InputEnd are both assigned a Date object with the time at the moment of assignment : typeof(InputStart) returns "object", same for InputEnd, you can now use InputStart.getDay() or any other method of Date. >> >>> InputStart = Date(YearT, MonthIndex, DayT, Start_HourT,Start_MinutesT, >>> 0,0); >>> InputEnd = Date(YearT, MonthIndex, DayT, End_HourT, End_MinutesT,0,0); Here you overwrite the Date object assigned to the InputStart and InputEnd with what is returned by a call to Date(like,stefan,wrote,whatever,arguments,you,put,here,won't,be,honoured) : a string representing the time at the moment of assignment. typeof(InputStart) returns "string", same for InputEnd. Because all this happens within a few milliseconds both strings are equal (the string is rounded to the second) which is why you get "true" if you test for their equality with (InputStart == InputEnd). >> >>> alert(Start_HourT + ":" + End_HourT); // output is 22:20 Correct >>> output >> >>> alert("==: " + (InputStart == InputEnd)); // Output is true?? Output >>> Not Correct >> >> If you want to call Date as a constructor, you need to write >> >> var InputStart = new Date(...); // note the 'new' operator >> >> Without 'new', Date() will ignore its arguments and return a string >> representing the current date/time instead of a Date object. >> >> -- >> stefan > > Thank you. That fixed my problem with the Date constructor. > What am I doing wrong here??? > > Thank you.. > > Bruce -- (�l�)
From: RobG on 28 Apr 2010 19:21
On Apr 28, 1:11 pm, bruce <bruc...(a)bellsouth.net> wrote: > The input for this this code is YearT=2010, MonthIndex=3, DayT = 27, > Start_HourT = 22, Start_MinutesT=15, > End_HourT = 20, End_MinutesT = 15 By convention, variable names starting with a capital letter signify constructors or, where all characters are upper case, constants. Code is much easier to read if neatly indented and, when posted to a news group, manually wrapped at about 70 characters. > > var InputStart = new Date(); > var InputEnd = new Date(); There's no point initialising variables with a value that you immediately overwrite. > InputStart = Date(YearT, MonthIndex, DayT, Start_HourT,Start_MinutesT, > 0,0); > InputEnd = Date(YearT, MonthIndex, DayT, End_HourT, End_MinutesT,0,0); Here you overwrite the intial values assigned to these variables, trivialising in the initial assignment. In ECMAScript, variables do not have a type (their values do), you can assign any type to any variable so there is no need to initialise them if you don't want to. > alert(Start_HourT + ":" + End_HourT); // output is 22:20 Correct > output > > alert("==: " + (InputStart == InputEnd)); // Output is true?? Output > Not Correct Consider (wrapped for posting): var yearT=2010, monthIndex=3, dayT = 27, start_HourT = 22, start_MinutesT=15, end_HourT = 20, end_MinutesT = 15, inputStart = new Date(yearT, monthIndex, dayT, start_HourT, start_MinutesT, 0, 0), inputEnd = Date(yearT, monthIndex, dayT, end_HourT, end_MinutesT, 0, 0); alert(inputStart == inputEnd); // false -- Rob |