Keithley 708B Reference Manual page 213

Section 6: Instrument programming
Arithmetic operators
Operator Description
addition
+
- subtraction
* multiplication
division
/
- negation (for example, c = -a)
exponentiation
^
Relational operators
Operator Description
less than
<
> greater than
less than or equal
<=
>= greater than or equal
not equal
~=
== equal
Logical operators
The logical operators in Lua are and, or, and not. All logical operators consider both false and
nil as false and anything else as true.
The operator not always returns false or true.
The conjunction operator and returns its first argument if this value is false or nil; otherwise, and
returns its second argument. The disjunction operator or returns its first argument if this value is
different from nil and false; otherwise, or returns its second argument. Both and and or use
shortcut evaluation, that is, the second operand is evaluated only if necessary.
Example
Code
print(10 or errorqueue.next())
print(nil or "a")
print(nil and 10)
print(false and errorqueue.next())
print(false and nil)
print(false or nil)
print(10 and 20)
6-22
Models 707B and 708B Switching Matrix Reference Manual
Output
1.0000000e+01
a
nil
false
false
nil
2.0000000e+01
707B-901-01 Rev. A / August 2010