Section 7: Introduction to TSP commands
Model DMM7510 7½ Digit Graphical Sampling Multimeter Reference Manual
7-14
DMM7510-901-01 Rev. B / May 2015
Variable types
Variables can be one of the following types.
Variable types and values
Variable type returned
Value
Notes
"nil"
not declared
The type of the value
nil
, whose
main property is to be different from
any other value; usually it represents
the absence of a useful value.
"boolean"
true or false
Boolean is the type of the values
false
and
true
. In Lua, both
nil
and
false
make a condition
false
; any other value makes it
true
.
"number"
number
All numbers are real numbers; there
is no distinction between integers
and floating-point numbers.
"string"
sequence of words or
characters
"function"
a block of code
Functions perform a task or compute
and return values.
"table"
an array
New tables are created with { }
braces. For example,
{1, 2, 3.00e0}.
"userdata"
variables
Allows arbitrary program data to be
stored in Lua variables.
"thread"
line of execution
To determine the type of a variable, you can call the
type()
function, as shown in the examples
below.
The output you get from these examples may vary depending on the data format that is set.
Example: Nil
x = nil
print(x, type(x))
nil nil
Example: Boolean
y = false
print(y, type(y))
false boolean
