CODEWITHSUNDEEP
tcl
user915783
user915783

Reputation: 699

using list variable in array set

I am learning TCL and found that I can initialize array as (k1,v1 is set of key values)

array set a2 {k1 v1 k2 v2}

however, when I try to use already existing list as

set var3 "k1 v1 k2 v2"
array set a2{$var3}

or 

set var3 [listk1 v1 k2 v2]
array set a2{$var3}

I get an error:

wrong # args: should be 'array set arrayName list"

What am I doing wrong?

Upvotes: 0

Views: 1400

Answers (2)

Peter Lewerin
Peter Lewerin

Reputation: 13252

Sometimes when a command invocation goes wrong it helps to look at the command as a list. In this way, one can see approximately how the command will look when it is ready to be executed. 

list array set a2{$var3}
# -> array set {a2{k1 v1 k2 v2}}

Hmm, no, that doesn't look right. There's supposed to be four words, and that third word looks weird.

How about if I put a space before the left brace?

list array set a2 {$var3}
# -> array set a2 {$var3}

Close, but no cigar. It looks like the braces are interfering with the variable substitution. What if I remove them?

list array set a2 $var3
# -> array set a2 {k1 v1 k2 v2}

And there was much rejoicing.

In this manner, one can experiment with the command structure and the quoting until one gets it right. Just a tip.

Upvotes: 2

Bryan Oakley
Bryan Oakley

Reputation: 385830

You are missing a space between the array name and the value. The syntax is "array set name value" but you were calling it like "array set namevalue"

array set a2 $var3

In the other example you included brackets around the variable, which would prevent the variable from being expanded. ${var3} will expand the same as $var3, but {$var3} will not.

Upvotes: 4

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