How To Find BASH Shell Array Length

bash

#!/bin/bash
# define array
# name server names FQDN 
NAMESERVERS=("ns1.nixcraft.net." "ns2.nixcraft.net." "ns3.nixcraft.net.")
# get length of an array
tLen=${#NAMESERVERS[@]}
# use for loop read all nameservers
for (( i=0; i<${tLen}; i++ ));
do
  echo ${NAMESERVERS[$i]}
done

Source

http://www.cyberciti.biz/faq/finding-bash-shell-array-length-elements/