reverse the order of characters in a string

Question

In string \"12345\", out string \"54321\". Preferably without third party tools and regex.

Answer 1

Presume that a variable 'var' has the value '123'

var="123"

Reverse the string and store in a new variable 'rav':

rav=$(echo $var | rev)

You'll see the 'rav' has the value of '321' using echo.

echo $rav