how to declare and print a variable in bash code example

Example 1: bash echo in variable

#Just use following structure to store output of command into a variable:
var=$(command)
#For example:
var=$(echo 'hi')	#store hi into var
var=$(ls)	#store list of files into var

Example 2: print variable in bash

#!/bin/bash  
echo  
echo "When single quote is used with string:"  
invitation='Welcome to javatpoint'  
echo $invitation  
echo  
echo "When double quote is used with string:"  
invitation="Welcome to javatpoint"  
echo $invitation  
echo  
echo "When variable is used with double quote:"  
Remark="Hello User!, $invitation"  
echo $Remark  
echo  
echo "When variable is used with single quote:"  
Remark='Hello User!, $invitation'  
echo $Remark  
echo