Why space cannot exist in array element index?

Altair Forum User

Hi all, how to understand the following error?

 

set city(Guang zhou) 'Guangdong'     

wrong # args: should be 'set varName ?newValue?'

 

set city(Guang\ zhou) 'Guangdong'

Guangdong

 

 

Why space cannot exist in array element index?

 

Roy

tinh

Array names (also variable name, proc name) must be one word

As tcl definition, string between 2 spaces is a word, or between 2 quotes or 2 braces

\  is a way to concate special characters to a word, so 

Guang\ zhou

Is same as

'Guang zhou'

and same as

{Guang zhou}

is a word.

but 

Guang zhou

are 2 words

Altair Forum User

Altair Forum User said:

Array names (also variable name, proc name) must be one word

As tcl definition, string between 2 spaces is a word, or between 2 quotes or 2 braces

\  is a way to concate special characters to a word, so 

Guang\ zhou

Is same as

'Guang zhou'

and same as

{Guang zhou}

is a word.

but 

Guang zhou

are 2 words

Hi @tinh

I try to use 'Guang zhou' or {Guang zhou}, the same error. However when using Guang,zhou, it is ok. How to understand?

 

 

Roy

tinh

Maybe :

set 'city(Guang zhou)' GuangZhou

 

so 'city(Guang zhou)' is a variable name, it is one word

array names ok to have multiple words 

Altair Forum User

Altair Forum User said:

Maybe :

set 'city(Guang zhou)' GuangZhou

 

so 'city(Guang zhou)' is a variable name, it is one word

array names ok to have multiple words 

Hi @tinh

I have tried your suggestion. 

set 'city(Guang zhou)' 'Guangdong'     it is ok.

How to understand why the previous statements were wrong? 

 

Roy

tinh

Just understand as whatever you want.

If you can't, you don't need it to learn tcl, simply neglect all spaces.