HackerRank Getting started with conditionals problem solution

In this HackerRank Getting started with conditionals problem solution if statements in Bash are often used in four important ways:

1. if…then…fi statements

2. if…then…else…fi statements  

3. if..elif..else..fi  

4. if..then..else..if..then..fi..fi.. (Nested Conditionals)

Their structure is

if [[ condition ]]

then

    do this

elif [[ condition ]]; then

    do this

else

    do this by default

fi

Read in one character from STDIN.

If the character is ‘Y’ or ‘y’ display “YES”.

If the character is ‘N’ or ‘n’ display “NO”.

No other character will be provided as input.

Problem solution.

read c
if [[ ${c^^} == Y ]];
then echo YES
else echo NO
fi

Second solution.

#!/bin/bash
read ch
if [ "$ch" == "y" ];
then
  echo "YES"
  elif  [ "$ch" == "Y" ];
  then
  echo "YES"
  else 
  echo "NO"
  fi

Third solution.

read -n 1 cmd
if [ "$cmd" == "y" ] || [ "$cmd" == "Y" ]; then
    echo "YES"
else
    echo "NO"
fi