Operators in the Flux language

Flux includes the following types of operators:

Also see:

Arithmetic operators

Arithmetic operators take two numerical values (either literals or variables) and perform a calculation that returns a single numerical value.

OperatorDescriptionExampleResult
-Subtraction3 - 21
*Multiplication2 * 36
/Division9 / 33
^Exponentiation2 ^ 38
%Modulo10 % 50

In the current version of Flux, values used in arithmetic operations must be of the same numeric type (integer or float). Operations with values of different numeric types will result in a type error.

Comparison operators

Comparison operators compare expressions and return true or false based on the comparison.

OperatorDescriptionExampleResult
==Equal to"abc" == "abc"true
!=Not equal to"abc" != "def"true
<Less than1 < 2true
>Greater than1 > 2false
<=Less than or equal1 <= 2true
>=Greater than or equal1 >= 2false
=~Equal to regular expression"abc" =~ /[a-z]*/true
!~Not equal to regular expression"abc" !~ /[0-9]*/true

The > and < operators also compare the lexicographic order of strings.

Logical operators

OperatorDescription
andReturns true if both operands are true. Otherwise, returns false.
orReturns true if any operand is true. Otherwise, returns false.

Short-circuit evaluation

Flux logical operators observe the short-circuiting behavior seen in other programming languages. The evaluation of the left-hand (LH) operand determines if the right-hand (RH) operand is evaluated.

• When the operator is and and the LH operand evaluates to false, the evaluation returns false without evaluating the RH operand.
• When the operator is or and the LH operand evaluates to true, the evaluation returns true without evaluating the RH operand.

Assignment operators

An assignment operator assigns a value to its left operand based on the value of its right operand.

OperatorDescriptionExampleMeaning
=Assign value of left expression to right expressionx = yx = y

Function operators

Function operators facilitate the creation of functions and control the flow of data through operations.

OperatorDescriptionExamplesMeaning
|>Pipe‑forwarddata |> function()Tables contained in the “data” variable are piped into the function.
<-Pipe‑receivetables=<-The “tables” variable or parameter is assigned to data piped into the operation. This operator is used for any data type passed into a function; not just table data.
=>Arrow(r) => r.tag1 == "tagvalue"The arrow passes an object or parameters into function operations.
()Function calltop(n:10)Call the top function setting the n parameter to 10 and perform the associated operations.

See Custom functions for examples of function operators is use.

String Operators

String operators concatenate or compare string values.

OperatorDescriptionExamplesResult
+Concatenation"ab" + "c""abc"
<Less than in lexicographic order"ant" < "bee"true
>Greater than in lexicographic order"ant" > "bee"false

Literal constructors

Literal constructors define fixed values.

OperatorDescription
[ ]List / array
{ }Object
""String

Miscellaneous operators

OperatorDescriptionExample
( )Logical groupingr._value / (r._value * 2)
,Sequence delimiteritem1, item2, item3
:Key-value separator{name: "Bob"}
.Member access / dot referencer._measurement

Operator precedence

The table below outlines operator precedence. Operators with a lower number have higher precedence.

PrecedenceOperatorDescription
1a()Function call
a[]Member or index access
.Member access
2* /Multiplication and division
3+ -Addition and subtraction
4== !=Comparison operators
< <=
> >=
=~ !~
5notUnary logical operator
existsNull check operator
6andLogical AND
7orLogical OR
8if then elseConditional