Arrays

arr=()	Create an empty array
arr=(1 2 3)	Initialize array
${arr[2]}	Retrieve third element
${arr[@]}	Retrieve all elements
${!arr[@]}	Retrieve array indices
${#arr[@]}	Calculate array size
arr[0]=3	Overwrite 1st element
arr+=(4)	Append value(s)
str=$(ls)	Save ls output as a string
arr=( $(ls) )	Save ls output as an array of files
${arr[@]:s:n}	Retrieve n elements starting at index s

#!/bin/bash
list=( $(ls) )
echo -e "${list[0]}"
echo -e "${list[1]}"
echo -e "${list[2]}"
echo -e "${list[@]}"

#!/bin/bash
declare -a arrPics

for file in *.jpg
do
    arrPics=(${arrPics[*]} "$file")
done

# Using [@]
echo -e '\nUsing [@] -----------------------------------'
for item in "${arrPics[@]}"
do    
    echo "ITEM: *** $item ***"
done

# Using [*]
echo -e '\nUsing [*] -----------------------------------'
for item in "${arrPics[*]}"
do    
    echo "ITEM: *** $item ***"
done

Source

https://delightlylinux.wordpress.com/2017/04/08/put-filenames-in-bash-array/