Section 10: Instrument programming
Series 3700A System Switch/Multimeter Reference Manual
10-22
3700AS-901-01 Rev. D/June 2018
String concatenation
String operators
Operator
Description
..
Concatenates two strings. If either argument is a number, it is coerced to a string
(in a reasonable format) before concatenation.
Example: Concatenation
print(2 .. 3)
print("Hello " .. "World")
Output:
23
Hello World
Operator precedence
Operator precedence in Lua follows the order below (from higher to lower priority):
•
^
(exponentiation)
•
not, -
(unary)
•
*, /
•
+,
–
•
..
(concatenation)
•
<
,
>
,
<=
,
>=
,
~=
,
!=
,
==
•
and
•
or
You can use parentheses to change the precedences in an expression. The concatenation ("
..
") and
exponentiation ("
^
") operators are right associative. All other binary operators are left associative. The
examples below show equivalent expressions.
Equivalent expressions
r offset < testValue/2+0.5
=
(r offset) <
((testValue/2)+0.5)
3+reading^2*4
=
3+((reading^2)*4)
Rdg < maxRdg and lastRdg <=
expectedRdg
=
(Rdg < maxRdg) and (lastRdg <=
expectedRdg)
-reading^2
=
-(reading^2)
reading^testAdjustment^2
=
reading^(testAdjustment^2)
