Model 2657A High Power System SourceMeter® Instrument Reference Manual
Section 6: Instrument programming
2657A-901-01 Rev. B/December 2012
6-13
Do not create variable names that are the same as the top level command names of Model 2657A
remote commands. Doing so will result in the loss of use of those commands. See
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}.
To determine the type of a variable, you can call the
type()
function, as shown in the examples
below.
Example: Nil
x = nil
print(x, type(x))
nil nil
Example: Boolean
y = false
print(y, type(y))
false boolean
NOTE
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