Tcl/Tk - Conditionals and Loops

Conditionals and Loops - Tcl/Tk module T203

Every programming language needs conditional commands such as "if" and the ability to repeat sections of code using commands such as "while". We cover these commands in this module, together with "for", "foreach", "switch" and conditional operators.

This topic is presented on public course Tcl Basics

Examples from our training material

diy	The for command
diy2	The foreach command
dthrow	The switch command
ftoc	F to C conversion - exercise
ftoc2	Is water a solid, a liquid or a gas?
group	The if command in Tcl
group4	deferred execution blocks with { and }
group5	if, elseif and else in Tcl
lazy	The ? : conditional operator
lunches	Lunches for each day of the week
morelunches	Lunches - different places to go
validlunches	Lunches - validating user input within range
wd	The while command in Tcl
wipats	More flexible alternative to a switch
wtot	breaking our of a Tcl loop

Opentalk forum discussions related to this topic

Tcl loops and conditionals
Looping down rather than up
Foreach loop inside a foreach loop

Pictures

The Tcl if command
Tcl course group
A private Tcl Course in Dublin

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from http://www.training-notes.co.uk.

Topics covered in this module

The if command.
deferred substitution.
The else and elseif parameters.
The while command.
Getting out of loops.
The for command.
The foreach command.
The switch command.
Conditional operators.
Combining conditions.
fconfigure.
Locating errors in your Tcl program.

Complete learning

If you are looking for a complete course and not just a information on a single subject, visit our Listing and schedule page.

Well House Consultants specialise in training courses in Tcl/Tk, Expect,Python, Perl, PHP, and MySQL. We run Private Courses throughout the UK (and beyond for longer courses), and Public Courses at our training centre in Melksham, Wiltshire, England. It's surprisingly cost effective to come on our public courses - even if you live in a different country or continent to us.

We have a technical library of over 600 books on the subjects on which we teach. These books are available for reference at our training centre. Also available is the Opentalk Forum for discussion of technical questions.