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.

Operator Description Example Result
+ Addition 1 + 1 2
- Subtraction 3 - 2 1
* Multiplication 2 * 3 6
/ Division 9 / 3 3
^ Exponentiation 2 ^ 3 8
% Modulo 10 % 5 0

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.

Operator Description Example Result
== Equal to "abc" == "abc" true
!= Not equal to "abc" != "def" true
< Less than 1 < 2 true
> Greater than 1 > 2 false
<= Less than or equal 1 <= 2 true
>= Greater than or equal 1 >= 2 false
=~ 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

Operator Description
not Returns true if right operand is false. Otherwise, returns false.
exists Returns false if right operand is null. Otherwise, returns true.
and Returns true if both operands are true. Otherwise, returns false.
or Returns 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.

Operator Description Example Meaning
= Assign value of left expression to right expression x = y x = y

Function operators

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

Operator Description Examples Meaning
|> Pipe‑forward data |> function() Tables contained in the “data” variable are piped into the function.
<- Pipe‑receive tables=<- 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 a record or parameters into function operations.
() Function call top(n:10) Call the top function setting the n parameter to 10 and perform the associated operations.

See Define custom functions for examples of function operators is use.

String Operators

String operators concatenate or compare string values.

Operator Description Examples Result
+ 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.

Operator Description
[ ] List / array
{ } Record
"" String

Miscellaneous operators

Operator Description Example
( ) Logical grouping r._value / (r._value * 2)
, Sequence delimiter item1, item2, item3
: Key-value separator {name: "Bob"}
. Member access / dot reference r._measurement

Operator precedence

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

Precedence Operator Description
1 a() Function call
a[] Member or index access
. Member access
2 |> Pipe forward
3 () => 1 FunctionLiteral
4 ^ Exponentiation
5 * / % Multiplication, division, and modulo
6 + - Addition and subtraction
7 == != Comparison operators
< <=
> >=
=~ !~
8 not Unary logical operator
exists Null check operator
9 and Logical AND
10 or Logical OR
11 if then else Conditional

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The future of Flux

Flux is going into maintenance mode. You can continue using it as you currently are without any changes to your code.

Flux is going into maintenance mode and will not be supported in InfluxDB 3.0. This was a decision based on the broad demand for SQL and the continued growth and adoption of InfluxQL. We are continuing to support Flux for users in 1.x and 2.x so you can continue using it with no changes to your code. If you are interested in transitioning to InfluxDB 3.0 and want to future-proof your code, we suggest using InfluxQL.

For information about the future of Flux, see the following: