Which is correct: “the variable X” or “variable X” or “the X variable”?

Question

I'm writing a description of my code. X is one of many variables.

Which version should I use to refer to X:

• "the variable X" or
• "variable X" or
• "the X variable" ?

Does the same rule applies to "method", "array" etc.?

Answer 1

My bet is on

the variable X

"The X variable" seems rather cloggy and I wouldn't use it personally.

Wikipedia has a similar understanding. Here an excerpt:

In mathematical terms, the dependent variable y represents the value of a function of x. To simplify formulas, it is often useful to use the same symbol for the dependent variable y and the function mapping x onto y.