Read txt file into an array in shell script

My configs.txt file is in the format

example1
example2
example3

I would like to read a text file configs.txt into an array and then loop through the array to perform a tar command to create a separate tarfile for each entry like example1.gz etc.

Not sure why you need an array

while read p; do
  echo "$p";
  # tar here
done < configs.txt 

for p in $(cat configs.txt); do 
  echo "$p";
  # tar here
done