Quick question about constant function

Question

Are all constant function, a multi-valued function?

Since, when we considering the constant function on real numbers, it's not one-to-one?

Answer 1

From the tag-info of multivalued function.

In Mathematics, set theory, a Multivalued function is defined as a left-total relation (that is, every input is associated with at least one output) in which at least one input is associated with multiple (two or more) outputs.

Constant function doesn't satisfy this condition since every input has exacty one input.

Perhaps you are asking if all constant function has domain cardinality that is more than $1$? This is not true as well, for example $f: \{1\}\to \{1\}, f(1)=1$