Operators (AND, OR)

AND  

[prabhucloudxlab@cxln4 ~]$ cat>hello.sh
#! bin/bash
# And Operators : Both conditions should be true

age=10
if [ "$age" -gt 18 ] && [ "$age" -lt 40 ]    
then
echo " age is correct"
else
echo " age is not correct"
fi

# Another Syntaxes  : 
# if [[ "$age" -gt 18  &&  "$age" -lt 40 ]] 
# if [ "$age" -gt 18  -a  "$age" -lt 40 ]

[prabhucloudxlab@cxln4 ~]$ sh hello.sh
 age is not correct
 
 

# Note: 

if [ "$age" -gt 18 ] && [ "$age" -lt 15 ] --->> 1st condition is false, 2nd condition  is true
#  age is not correct

if [ "$age" -gt 9 ] && [ "$age" -lt 15 ]  --->> both conditions is true

#  age is correct




#=======================================================

OR

[prabhucloudxlab@cxln4 ~]$ cat>hello.sh
#! bin/bash
# OR Operators : One condition is true

age=10
if [ "$age" -gt 18 ] || [ "$age" -lt 40 ]    
then
echo " age is correct"
else
echo " age is not correct"
fi

# Another Syntaxes  : 
# if [[ "$age" -gt 18  ||  "$age" -lt 40 ]] 
# if [ "$age" -gt 18  -o  "$age" -lt 40 ]

[prabhucloudxlab@cxln4 ~]$ sh hello.sh
 age is correct