Bash Array

arr[0]='hello'
arr[1]='hello'

declare -a arr=(1 2 3)
declare -a arr=('hello' 'Red hat')

arr=(1 2 3)

echo ${arr[0]}

echo ${arr[@]}

echo ${#arr[@]}

arr[0]=1
arr[3]=3

echo ${!arr[@]}

arr=(this is an array)

echo ${arr[@]:1:2}

// is an

arr=(this is an array)

echo ${arr[0]:0:3}

//thi

Unix=('Debian' 'Red hat' 'Ubuntu')
echo ${Unix[@]/Ubunti/SCO Unix}

Debian Red hat SCO Unix

arr=(this is an array)
arr=("${arr[@]}" I am Sean)
echo ${arr[4]}
//I

arr=(a b c)
unset arr[2]
echo ${arr[@]}

$ cat arraymanip.sh
Unix=('Debian' 'Red hat' 'Ubuntu' 'Suse' 'Fedora' 'UTS' 'OpenLinux');
pos=3
Unix=(${Unix[@]:0:$pos} ${Unix[@]:$(($pos + 1))})
echo ${Unix[@]}

$./arraymanip.sh
Debian Red hat Ubuntu Fedora UTS OpenLinux

$ cat arraymanip.sh
#!/bin/bash
declare -a Unix=('Debian' 'Red hat' 'Ubuntu' 'Suse' 'Fedora');
declare -a patter=( ${Unix[@]/Red*/} )
echo ${patter[@]}

$ ./arraymanip.sh
Debian Ubuntu Suse Fedora

array1=(a b c)
array2=("${array1[@]}")

array1=(a b c)
array2=(d e f)
array3=("${array1[@]}" "${array2[@]}")

array=(...)
unset array

filecontent=($(cat logfile))

for row in "${filecontent[@]}"; do
	echo $row
done

for in in "${array[@]}"; do
	echo $i
end

for i in "my" "name" "is" "sean"; do
...
done


for i in {a,b,c,d}; do
	echo $i
done

for i in {1..10}; do
	echo $i
done

# print all the file in the current location
for i in $(ls); do
	echo $i
done

declare -A animals
animals=(["key"]="value")

Then use them just like normal arrays.  "${animals[@]}" expands the values, "${!animals[@]}" (notice the !) expands the keys. Don't forget to quote them:

get by key

echo "${animals["moo"]}"

loop the hash
for sound in "${!animals[@]}"; do echo "$sound - ${animals["$sound"]}"; done