change array value while looping in bash

Question

The code

SourceFolder[0]=""
SourceFolder[1]="inbound2"
SourceFolder[2]="inbound3"

for i in "${!SourceFolder[@]}"
do    
    if [ -z "${SourceFolder[$i]}"]; then
        ${SourceFolder[$i]} = "TEST"
    fi
done

${SourceFolder[$i]} = "TEST" - doesn't work

it says

=: command not found

How to change value in current loop index in an array?

Didn't the proposed solution to your [previous question](http://stackoverflow.com/questions/20653134/is-it-possible-to-set-a-default-value-for-sparse-array-in-bash) work for you? — devnull, Dec 18 '13 at 09:05
@devnull yes, the solution in that question is working. But in that case if array size will change I have to edit code with that additional looping, which I don't like( that's why I've decided to go in this way — VextoR, Dec 18 '13 at 09:08

score 3 · Accepted Answer · edited May 23 '17 at 11:58

3

Because of the first space = is not interpreted as an assignment. There is a full explanation on So.

Btw ${SourceFolder[$i]} evaluate the array element, which is not what you want to do. For instance for the first one it is the empty string.

Replaces with SourceFolder[$i]=

edited May 23 '17 at 11:58

Community

1
1

answered Dec 18 '13 at 09:05

UmNyobe

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This helped! btw, it has another error in if `[ -z "${SourceFolder[$i]}"]; then` it says `[: missing `]'` why is that? – VextoR Dec 18 '13 at 09:12
2

again, watch your spaces. should be `[ -z "${SourceFolder[$i]}" ]` – UmNyobe Dec 18 '13 at 09:17

score 1 · Answer 2 · answered Feb 13 '19 at 12:39

You must change indexnumber in the your array:

ARRAYNAME[indexnumber]=value

ok, you have array is:

array=(one two three)

you can add count to your script for initialize and change element for array indexnumber, example:

#!/bin/bash

count=0
array=(one two three)

for i in ${array[@]}
do
  echo "$i" 
  array[$count]="$i-indexnumber-is-$count"
  count=$((count + 1))
  echo $count
done

echo ${array[*]}

Result:

bash test-arr.sh 
one
1
two
2
three
3
one-indexnumber-is-0 two-indexnumber-is-1 three-indexnumber-is-2

change array value while looping in bash

2 Answers2