HTML and CSS Reference
In-Depth Information
Creating Program Loops
• To create a for loop, use looping structure
for ( start ; continue ; update ) {
where start is an expression that sets the initial value of a counter variable,
continue is a Boolean expression that must be true for the loop to continue, update
is an expression that indicates how the value of the counter variable should change
each time through the loop, and commands is the JavaScript commands that are run
each time through the loop.
• To create a while loop, use the following:
while ( continue ) {
• To create a do / while loop, use the following:
do {
while ( continue );
• To loop through the contents of an array, enter the for loop
for (var i = 0; i < array .length; i ++) {
commands involving array [ i ]
where i is a counter variable representing the indices of the array items and array is
the array to be looped through.
With this information, you can create a function that employs arrays and a for loop
to create a row displaying the names of the seven days of the week. First, you'll need to
use the following code to create the dayName array containing the three-letter abbrevia-
tions for the days:
var dayName = [“Sun”, “Mon”, “Tue”, “Wed”, “Thu”, “Fri”, “Sat”];
Then, you'll loop through the values of the array, displaying each value in a header cell
with the class name calendar_weekdays , as follows:
for (var i = 0; i < dayName.length; i++) {
document.write(“<th class='calendar_weekdays'>”
+ dayName[i] + “</th>”);
You'll add these commands to a new function named writeDayNames(), and then you'll
apply the function to your monthly calendar.
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