Repeating elements

At some point, you may want to populate a list with a number of repeated elements. This may be for testing or various other reasons. To accomplish this, Tcl provides the lrepeat command. The syntax is as follows:

lrepeat number element1 element2 …

How to do it…

In the following example, we will use the lrepeat command to create a list of repeated characters. Return values from the commands are provided for clarity. Enter the following command:

% lrepeat 3 a
a a a

How it works…

The lrepeat command creates a list of the size referenced in the number variable multiplied by the number of elements.

There's more…

In the following example we will combine lrepeat commands to create multiple lists containing repeated characters. Return values from the commands are provided for clarity. Enter the following command:

% lrepeat 3 [lrepeat 3 0]
{0 0 0} {0 0 0} {0 0 0}

As you can see, by combining the lrepeat command we have created a list containing the same element repeated three times...