#### 1.3.4 The `info` function ¶

If you want to know the data type and dimensions of a variable, use the `info` function. Unlike `help`, which is intended to tell you what a thing means, `info` simply tells what a thing is.

    > info, theta
     array(double,200)
    > info, E
     array(double)

Here, `double` means “double precision floating point number”, which is the default data type for any real number. The default integer data type is called `long`. (Both these names come from the C language, which gives them a precise meaning.)

Notice that the scalar value `E` is, somewhat confusingly, called an “array”. In fact, a scalar is a special case of an array with zero dimensions. The `info` function is designed to print a Yorick expression which will create a variable of the same data type and shape as its argument. Thus, `array(double,200)` in an expression would evaluate to an array of 200 real numbers, while `array(double)` is a real scalar (the values are always zero).

Using `info` on a non-numeric quantity (a file object, a function, etc.) results in the same output as the `print` function. If an array of numbers might be large, try `info` before `print`.