Bash shell script undefined array item value question


 
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# 1  
Old 11-19-2013
Question Bash shell script undefined array item value question

Hello,

I'm new here. I test these expressions's value in my script :
(in centOS 6 )
Code:
#!/bin/bash
array['test']='something'

echo "############"
echo ${array["test1"]}
echo ${array["test2"]}
echo ${array["5"]}
echo "############"

The output result is :
Code:
#################
something
something

#################

Why the value of ${array["test1"]} and ${array["test2"]} is "something" instead of empty ?
Because they are not defined just as ${array["5"]}, however the value of ${array["5"]} is empty and it's correct.

Thanks in advance for your help.

Last edited by Franklin52; 11-19-2013 at 05:32 AM.. Reason: Please use code tags
# 2  
Old 11-19-2013
bash does not support associative arrays. You can only use integers as indexes.
# 3  
Old 11-19-2013
bash do support associative arrays.
they only need to be declared:
Code:
declare -A assoAr
assoAr[subscript]="any value"
assoAr[aosubscript]="another value"
printf '%s\n' "${assoAr[@]}"
any value
another value

This User Gave Thanks to daPeach For This Post:
# 4  
Old 11-19-2013
I stand corrected. When was this feature intoduced?
# 5  
Old 11-19-2013
Quote:
When was this feature intoduced?
bash 4
# 6  
Old 11-19-2013
Thanks ! after add the declaration
declare -A array

It works as expected : The undefined item of array has empty value.
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