The IF function.
if function
The IF function can assign a value to a cell based on a logical test.
The IF function is exactly what you need to assign a value based on a logical test, as in: =IF(A1>5,"Greater","Less" than or equals to") This will result in a cell whose value is the string "Greater" if A1 contains a value greater than 5 and "Less than or equals to" if it is not greater than 5. You can also put numbers or even formulas in the values to assign.
Function
It is exogenous.
Independent variables are the input value of a function (usually x) and dependent variables are the output value of the function (usually y).
A set of ordered pairs that assign to each x-value exactly one y-value is called a function.
AnswerYes, it can. For instance, if your function returns double you can assign the function call to a variable of type double.AnswerNo, only the returned value, of course.
It is a value in the co-domain [range] of the function.
the output of a function; a variable whose value depends on the value of the input.
True
isdigit is an example (see in ctype.h)