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Our plans were to retire in summer 2020 and see the world, but Coronavirus has lead us into a lot of lockdown programming in Python 3 and PHP 7.
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variable declaration only

Posted by neo (The Architect), 2 May 2005
How do I just declare a variable in TCL?
or at least how do I weed out null "{}" entries from a list?
I needed to create a list so I did an
lappend $var;

but this gives it a null entry i think. Is there any other way tp do this. I can't do a
in the for loop as i don't know when i will enter that part of the loop.

Posted by admin (Graham Ellis), 2 May 2005
All variables in Tcl contain strings (slight exception - arrays contain one or more strings).  If you want to remove empty strings from a list, try something like


set wotsit [list tom "" dick "" "" harry ""]
puts $wotsit

while {[set where [lsearch -exact $wotsit ""]] > -1} {
       set wotsit [lreplace $wotsit $where $where]

puts $wotsit

Testing ....

earth-wind-and-fire:~/may05 grahamellis$ tclsh wi
tom {} dick {} {} harry {}
tom dick harry
earth-wind-and-fire:~/may05 grahamellis$

Yes, that works

Posted by neo (The Architect), 3 May 2005
Thanks a lot for that. It works now.
I have another query though. I've posted it here;action=display;num=1115113410

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