How to declare Boolean variables in bash and use them in a shell script

In Bash, you can declare Boolean variables using the declare command and the -b option. The value of a Boolean variable can be either true or false.

Here is an example of how to declare a Boolean variable in Bash and use it in a shell script:

# Declare the variable as a Boolean
declare -b flag=true

# Check the value of the variable in an if statement
if [ "$flag" = true ]; then
  echo "Flag is set to true"
else
  echo "Flag is set to false"
fi

You can also use the =1 and =0 syntax to set the value of a Boolean variable:

# Set the variable to true
flag=1

# Set the variable to false
flag=0