# Documentation

## Special Values

Several functions return important special values that you can use in your own program files.

Function

Return Value

Most recent answer (variable). If you do not assign an output variable to an expression, MATLAB® automatically stores the result in `ans`.

Floating-point relative accuracy. This is the tolerance the MATLAB software uses in its calculations.

Largest 8-, 16-, 32-, or 64-bit integer your computer can represent.

Smallest 8-, 16-, 32-, or 64-bit integer your computer can represent.

Largest floating-point number your computer can represent.

Smallest positive floating-point number your computer can represent.

`3.1415926535897...`

Imaginary unit.

Infinity. Calculations like `n/0`, where `n` is any nonzero real value, result in `inf`.

Not a Number, an invalid numeric value. Expressions like `0/0` and `inf/inf` result in a `NaN`, as do arithmetic operations involving a `NaN`. Also, if `n` is complex with a zero real part, then `n/0` returns a value with a `NaN` real part.

Computer type.

MATLAB version string.

Here are some examples that use these values in MATLAB expressions.

```x = 2 * pi x = 6.2832 A = [3+2i 7-8i] A = 3.0000 + 2.0000i 7.0000 - 8.0000i tol = 3 * eps tol = 6.6613e-016 intmax('uint64') ans = 18446744073709551615```