Advanced Bash−Scripting Guide

echo "Elements in array2: ${array2[@]}"
echo
echo "Length of first element in array0 = ${#array0}"
echo "Length of first element in array1 = ${#array1}"
echo "Length of first element in array2 = ${#array2}"
echo
echo "Number of elements in array0 = ${#array0[*]}" # 3
echo "Number of elements in array1 = ${#array1[*]}" # 1 (surprise!)
echo "Number of elements in array2 = ${#array2[*]}" # 0
}
# ===================================================================
ListArray
# Try extending those arrays
# Adding an element to an array.
array0=( "${array0[@]}" "new1" )
array1=( "${array1[@]}" "new1" )
array2=( "${array2[@]}" "new1" )
ListArray
# or
array0[${#array0[*]}]="new2"
array1[${#array1[*]}]="new2"
array2[${#array2[*]}]="new2"
ListArray
# When extended as above; arrays are 'stacks'
# The above is the 'push'
# The stack 'height' is:
height=${#array2[@]}
echo
echo "Stack height for array2 = $height"
# The 'pop' is:
unset array2[${#array2[@]}−1] # Arrays are zero based
height=${#array2[@]}
echo
echo "POP"
echo "New stack height for array2 = $height"
ListArray
# List only 2nd and 3rd elements of array0
from=1
# Zero based numbering
to=2 #
declare −a array3=( ${array0[@]:1:2} )
echo
echo "Elements in array3: ${array3[@]}"
# Works like a string (array of characters)
# Try some other "string" forms
Advanced Bash−Scripting Guide
# Replacement
declare −a array4=( ${array0[@]/second/2nd} )
echo
echo "Elements in array4: ${array4[@]}"
Chapter 26. Arrays 296