"Okay now I'm also confused...."

https://arbital.com/p/3lp

by Alexei Andreev May 14 2016


The image of a function is not to be confused with the codomain, which is the type of output that the function produces\. For example, the function $~$f(x)\=1$~$ that always returns $~$1$~$ has image $~$\\{1\\}$~$, even though its codomain is the set of all numbers\.

Okay now I'm also confused. (Eric Rogstad)
Why don't we just say its codomain is {1}?