CODEWITHSUNDEEP
arraysbash
Sai Koti
Sai Koti

Reputation: 177

bash Array is not updated with the new assignment

Below is the code that i tried

app+=(0)
top+=(1 2 3 4 5)
for i in ${app[@]}
do
echo $i th time
app=${top[@]}
done

the output 

(09:01:12)-> ./loop.sh



0 th time

please advice why cant the new value is updated and only once the code is running

Upvotes: 0

Views: 367

Answers (2)

perreal
perreal

Reputation: 98028

I don't know what you really want to do but you can modify this to suit your needs:

app+=(0)
top+=(1 2 3 4 5)
for ((i=0; i<${#app[@]};++i)); do
    echo "$i" th time, "${app[i]}" element
    app=(${top[@]})
done

Gives:

0 th time, 0 element
1 th time, 2 element
2 th time, 3 element
3 th time, 4 element
4 th time, 5 element

Upvotes: 1

iBug
iBug

Reputation: 37267

In your code, ${app[@]} is expanded only once, so it makes no different from for i in 0. You can't modify the loop range once the loop has started. Your best bet could be using some other tricks like

ind=0
loop() {
    eval $1=${app[$ind]}
    (( ind++ ))
    return 0
}

while loop i
do
    # Now you can modify $app
done

But at last, it's not recommended to attempt to change the loop range during it.

Upvotes: 0

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