Accessing an array item by index in bash

Question

I have the following code:

PROJECT_TYPES="iPad iPhone"
ANT_TARGET_NAMES="ipadf ipaf"

INDEX=0

for PROJECT_TYPE in $PROJECT_TYPES; do

echo "${PROJECT_TYPE} => ${ANT_TARGET_NAMES[$INDEX]}"

let "INDEX++"
done

This displays the following lines:

iPad => ipadf ipaf
iPhone =>

How can I change the code so it displays:

iPad => ipadf
iPhone =>  ipaf

???

Thanks in advance

Mike

foo="bar baz" creates a string with the contents bar baz. In certain contexts, strings can be split into sequences because of the way they're interpolated (whitespace splitting), but they are not lists. — Daenyth
– Daenyth, Commented Sep 7, 2011 at 16:28

ennuikiller · Accepted Answer · 2011-09-07 16:26:23Z

2

The correct way to do this is:

INDEX=0
PROJECT_TYPES=(iPad iPhone)
ANT_TARGET_NAMES=(ipadf ipaf)

for PROJECT_TYPE in ${PROJECT_TYPES[*]} 
do 
echo "${PROJECT_TYPE} => ${ANT_TARGET_NAMES[$INDEX]}"  
let "INDEX++" 
done

answered Sep 7, 2011 at 16:26

ennuikiller

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Comments

glenn jackman · Accepted Answer · 2011-09-07 17:14:07Z

1

bash 4 has associative arrays so you could write:

declare -A targets=([iPad]=ipadf [iPhone]=ipaf)
for project_type in "${!targets[@]}"; do
  printf "%s => %s\n" "$project_type" "${targets[$project_type]}"
done

Otherwise, declare two arrays as in ennuikiller's answer, but I would iterate over the indices directly

projects=(iPad iPhone)
targets=(ipadf ipaf)
for (( i=0; i < ${#projects[@]}; i++ )); do
  printf "%s => %s\n" "${projects[$i]}" "${targets[$i]}"
done

answered Sep 7, 2011 at 17:14

glenn jackman

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1 Comment

Emidee Over a year ago

Thanks, but I have bash 3 here

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