JavaScript EditorFree JavaScript Editor     DHTML Editor 



Main Page Previous Section Next Section

15.6 Greeting Users with Their Time of Day

NN 2, IE 3

15.6.1 Problem

You want your page to include a greeting pertinent to the user's part of the day, such as "Good morning" or "Good afternoon".

15.6.2 Solution

First, create a function that returns strings associated with each day part, as calculated by a fresh Date object:

function dayPart( ) {
    var oneDate = new Date( );
    var theHour = oneDate.getHours( );
    if (theHour < 12) {
        return "morning";
    } else if (theHour < 18) {
        return "afternoon";
    } else {
        return "evening";
    }
}

To accommodate both scriptable and unscriptable browsers, be sure to encase the script statement inside HTML comment tags, and include the noscript element with the text to display for unscriptable browsers.

<script language="JavaScript" type="text/javascript">
<!--
document.write("Good " + dayPart( ) + " and welcome")
//-->
</script>
<noscript>Welcome</noscript>
 to GiantCo.

15.6.3 Discussion

As the page loads, it creates an instance of a Date object. By omitting the parameter for the Date object constructor function, the current time and date are used to generate the object. A Date object instance is not a ticking clock, but rather a snapshot of the clock when the object was created. The accuracy of the time is strictly dependent upon the computer's internal clock setting.

A Date object has numerous functions for getting and setting components of the date, ranging from the millisecond to the year. The getHours( ) method used in the Solution returns a number between 0 and 23, corresponding to the 24-hour clock set to the user's local time. The dayPart( ) function simply divides the day into three portions, breaking at noon and 6 P.M. to supply day parts ranging through morning, afternoon, and evening.

15.6.4 See Also

Recipe 2.9 through Recipe 2.11 for information about working with the Date object.

    Main Page Previous Section Next Section
    



    JavaScript EditorJavaScript Checker     DHTML Editor


    ©