Keithley 3721-ST - Page 333

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
reading + offset < testValue/2+0.5
=
(reading + 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)