Making loops in shell script

(1)

for i in $(seq 1 10)

do 

 echo $i

 //do some stuff

done

(2)

for i in `seq 1 10`
do

 //do some stuff

done

(3)

for i in 1 2 3 4 5 6 7 8 9 10

do

 //do some stuff 

done

(4) 

for i in {1..10} {15..20}
do //do some stuff

done

(5)

s=0

while [ "$s" -lt 10 ]; do s=`echo $s+1|bc`; echo $s; done

(6)

for (( i=1; c<=10; i++ ))
do
 // do some stuff
done
 

(7) Loops through files in a directory

files=( $( ls /path/to/directory ) )  #list files in an array
n=${#files[*]}   #array size

for (( i=0; i < n; i++ ))

do 

 echo File number $((i+1)) is ${files[$i]}

done