Bash shell script assignment operations

#!/bin/bash

#assignments

x=10
y=$x

echo "$x $y"

a=1.2
b=$a
echo "$a $b"

p="abc"
q=$p

echo "$p $q"

readonly n=100
s=$n

echo "$n $s"

#array to scalar

a=( 1 2 3 4 5 )
echo "${a[@]}"

m=${a[0]}
echo "a[0] $m"

arr=( "aa" "bb" "cc")
echo "${arr[@]}"

m=${arr[0]}
echo "arr[0] $m"

p=( "${arr[@]}" )

echo "p -> ${p[@]} "

v=100
a[2]=$v
echo "${a[@]}"

u="dd"
arr[1]=$u
echo "${arr[@]}"