Advanced Bash−Scripting Guide

echo ${colors[$index]}
let "index = $index + 1"
done
# Each array element listed on a separate line.
# If this is not desired, use echo −n "${colors[$index]} "
#
# Doing it with a "for" loop instead:
# for i in "${colors[@]}"
# do
# echo "$i"
# done
# (Thanks, S.C.)
echo
# Again, list all the elements in the array, but using a more elegant method.
echo ${colors[@]}
# echo ${colors[*]} also works.
echo
# The "unset" command deletes elements of an array, or entire array.
unset colors[1]
# Remove 2nd element of array.
# Same effect as colors[1]=
echo ${colors[@]}
# List array again, missing 2nd element.
unset colors
echo; echo −n "Colors gone."
echo ${colors[@]}
exit 0
Advanced Bash−Scripting Guide
# Delete entire array.
# unset colors[*] and
#+ unset colors[@] also work.
# List array again, now empty.
As seen in the previous example, either ${array_name[@]} or ${array_name[*]} refers to all the elements
of the array. Similarly, to get a count of the number of elements in an array, use either ${#array_name[@]}
or ${#array_name[*]}. ${#array_name} is the length (number of characters) of ${array_name[0]}, the first
element of the array.
Example 26−4. Of empty arrays and empty elements
#!/bin/bash
# empty−array.sh
# Thanks to Stephane Chazelas for the original example,
#+ and to Michael Zick for extending it.
# An empty array is not the same as an array with empty elements.
array0=( first second third )
array1=( '' ) # "array1" has one empty element.
array2=( ) # No elements... "array2" is empty.
echo
ListArray()
{
echo
echo "Elements in array0: ${array0[@]}"
echo "Elements in array1: ${array1[@]}"
Chapter 26. Arrays 295