For Loops

Another useful programming structure is the loop. JavaScript provides several ways to repeat commands easily. Let's start with the for loop. The following html was written with JavaScript:

The for loop requires three parameters:

• The first parameter is the initial setting for the loop variable. In this case we initialize a variable (i) and set i to 1.
• The second parameter is the condition, which must remain true to keep the loop running. In this case, the condition is "as long as i is less than or equal to 10."
• The third parameter is the increment expression which is often used to increment the variable. In this case we add 1 to i at each iteration of the loop.

The same three parameters are used, but with abbreviated coding. i=1 initializes the starting variable, and i++ adds 1 to the variable each time the loop runs (iteration).