I am trying to replace the word "Apples" with "Cantaloupe" in my 'copy' array. What I am doing now is not throwing errors, but no change occurs in the copy array.
#!/bin/bash
fruits=("Oranges" "Apples" "Bananas" "Grapes")
echo "Original list:"
echo "${fruits[@]}"
copy=("${fruits[@]}")
for i in ${copy[@]}
do
if [[ copy[$i] == "Apples" ]]; then
copy[$i]="Cantaloupe"
fi
done
echo "Copied list:"
echo "${copy[@]}"
My output:
Original list:
Oranges Apples Bananas Grapes
Copied list:
Oranges Apples Bananas Grapes
In your original approach you are looping over the keys in the array using which you would not be able to get the index of that element to replace.
You need to change to modify the logic to loop over indices of the array as
for i in "${!copy[@]}"; do
if [[ ${copy[$i]} == "Apples" ]]; then
copy[$i]="Canteloupe"
fi
done
should solve your problem.
The construct for i in "${!copy[@]}"; do
is for looping with indices of the array starting from 0
to size of the array which lets you to replace the element in the index where you find the required string.
Expanding the answer to point out the difference when using either of array iteration ways.
Looping over indices
for i in "${!copy[@]}"; do
printf "%s\t%s\n" "$i" "${copy[$i]}"
done
prints
0 Oranges
1 Apples
2 Bananas
3 Grapes
and over keys
for i in "${copy[@]}"; do
printf "%s\n" "$i"
done
produces,
Oranges
Apples
Bananas
Grapes