On Sun, Nov 21, 2021 at 07:18:09PM +0000, Darac Marjal wrote: > You probably already know that if you write: > > i = 65 > > then several things happen:
Only one thing happens: bash tries to run the command named "i" and you will almost certainly get an error message saying "command not found". If you want a variable assignment, you must not have spaces around the = sign. i=65 This assigns the string "65" to the variable named i. > So, that's a very basic method of storing the variable. At this point, > we know that the variable "i" equals 65, right? Well, how do we know > that the variable doesn't hold the character "A", or that it's not an > array? So, there must be a table somewhere else that tells us "what KIND > of data is stored in 'i'?". Bash does not store integer variables. Ever. Only string variables. Using "declare -i" does not change that. It only makes bash undergo some weird gyrations every time a new string value is assigned to the variable in question. (And overloads the += operator, because life wasn't confusing enough yet.) Many people think "Oh, if I use declare -i, bash will store my values as integers, and arithmetic will become more efficient, because bash won't have to keep doing string-to-integer conversions all the time." This is incorrect. Everything is stored as a string.
