Operators in Verse | Fortnite Documentation

Operators are special functions defined in the Verse programming language to perform actions such as math operations on their operands. For example, in the expression 1 + 2, the + is an operator, and 1 and 2 are both operands.

There are three formats for operators that you’ll see in Verse:

Prefix: There is only one operand and the operator is before the operand.
Infix: There are two operands and the operator is between the operands.
Postfix: There is only one operand and the operator is after the operand.

This page describes all the operators you can use in Verse, how they work, and their order of evaluation when used in combination with other operators.

List of All Operators and Operator Precedence

When multiple operators are used in the same expression, they are evaluated in the order of highest to lowest precedence. The table below lists all built-in operators in Verse and their precedence.

Name	Operator	Description	Operator Format	Operator Precedence	Example
Query	`?`	The `?` operator checks if a `logic` value is `true`. See Query for more details.	Postfix	9	`BossDefeated?`
Not	`not`	The `not` operator negates the success or failure of an expression. See Not for more details.	Prefix	8	`not BossDefeated?`
Positive	`+`	You can use the `+` operator as a prefix to a number to help align your code visually, but it won't change the value of the number. See Math for more details.	Prefix	8	`+MyScore`
Negative	`-`	You can use the operator `-` as a prefix to a number to negate the number value. See Math for more details.	Prefix	8	`-MyScore`
Multiplication	`*`	The `*` multiplies two number values together. See Math for more details.	Infix	7	`MyScore * ScoreMultiplier`
Division	`/`	The `/` operator divides the first number operand by the second number operand. Integer division is failable. See Math for more details.	Infix	7	`MyScore / ScorePenalty`
Addition	`+`	The `+` operator adds two number values together. When used with strings and arrays, the two values are concatenated. See Math for more details.	Infix	6	`MyScore + ScoreBonus`
Subtraction	`-`	The `-` operator subtracts the second number operand from the first operand. See Math for more details.	Infix	6	`MyScore - ScorePenalty`
Addition assignment	`set +=`	With this operator, you can combine addition and assignment in the same operation to update a variable's value. See Math for more details.	Infix	5	`set MyScore += ScoreBonus`
Subtraction assignment	`set -=`	With this operator, you can combine subtraction and assignment in the same operation to update a variable's value. See Math for more details.	Infix	5	`set MyScore -= ScorePenalty`
Multiplication assignment	`set *=`	With this operator, you can combine multiplication and assignment in the same operation to update a variable's value. See Math for more details.	Infix	5	`set MyScore *= ScoreMultiplier`
Division assignment	`set /=`	With this operator, you can combine division and assignment in the same operation to update a variable's value, unless the variable is an integer. See Math for more details.	Infix	5	`set MyScore /= ScorePenalty`
Equal to	`=`	The `=` operator succeeds when the left operand is equal to the right operand. Fails otherwise. See Comparison for more details.	Infix	4	`MyScore = HighScore`
Not equal to	`<>`	The `<>` operator succeeds when the left operand is not equal to the right operand. Fails otherwise. See Comparison for more details.	Infix	4	`MyScore <> HighScore`
Less than	`<`	The `<` operator succeeds when the left operand is less than the right operand. Fails otherwise. See Comparison for more details.	Infix	4	`MyScore < HighScore`
Less than or equal to	`<=`	The `<=` operator succeeds when the left operand is less than or equal to the right operand. Fails otherwise. See Comparison for more details.	Infix	4	`MyScore <= HighScore`
Greater than	`>`	The `>` operator succeeds when the left operand is greater than the right operand. Fails otherwise. See Comparison for more details.	Infix	4	`MyScore > HighScore`
Greater than or equal to	`>=`	The `>=` operator succeeds when the left operand is greater than or equal to the right operand. Fails otherwise. See Comparison for more details.	Infix	4	`MyScore >= HighScore`
And	`and`	The `and` operator succeeds only when all the operands succeed. See And / Or Operators for more details.	Infix	3	`BossDefeated? and TargetScoreReached?`
Or	`or`	The `or` operator succeeds if at least one of the operands succeeds. See And / Or Operators for more details.	Infix	2	`BossDefeated? or TargetScoreReached?`
Variable and constant initialization	`: =`	With this operator, you can store values in a constant or variable. See Constants and Variables for more details.	Infix	1	`MyScore : int = 42`
Variable assignment	`set =`	With this operator, you can update the values stored in a variable. See Constants and Variables for more details.	Infix	1	`set MyScore = 42`

If there are operators with the same precedence in the same expression, then they are evaluated left to right. For example in the expression 3*2/4, both operators * and / have the same precedence, so 3*2 is evaluated first and its result becomes the left operand for the / operator.

You can change the order in which operators are evaluated by grouping expressions with (). For example, (1+2)*3 and 1+(2*3) don't evaluate to the same result. See Grouping for more details.

Comparison

You can control the success and failure flow with comparison expressions, which use the inequality and equality operators. Comparison expressions are failable, so you can only use comparison operators in failure contexts, such as in if expressions.

The table below describes each operator and what types it supports. All comparison operators use the infix format.

Operator	Supported BUilt-In Types	Description
`<`	`float` `int`	The `<` operator succeeds when the left operand is less than the right operand. Fails otherwise.
`<=`	`float` `int`	The `<=` operator succeeds when the left operand is less than or equal to the right operand. Fails otherwise.
`>`	`float` `int`	The `>` operator succeeds when the left operand is greater than the right operand. Fails otherwise.
`>=`	`float` `int`	The `>=` operator succeeds when the left operand is greater than or equal to the right operand. Fails otherwise.
`<>`	`float` `int` `logic` `string` `enum`	The `<>` operator succeeds when the left operand is not equal to the right operand. Fails otherwise.
`=`	`float` `int` `logic` `string` `enum`	The `=` operator succeeds when the left operand is equal to the right operand. Fails otherwise.

Both <>and = are also supported for array, map, tuple, and class instances, but with restrictions. The array, map, and tuple instances can only contain supported types, and class instances are only supported if they contain at least one var member.

Decision

You can control the success and failure flow with decision expressions, which use the operators not, and, and or. Decision expressions are failable, so you can only use comparison operators in failure contexts, such as in if expressions. You can use any expressions that succeed or fail with decision operators.

Not Operator

The decision operator not negates the success or failure of an expression. The not operator uses the prefix format.

For example, when expression fails, not expression will succeed. When expression succeeds, not expression will fail and the effects of expression are never committed (as if the expression never happened).

For example, after the following code is executed, Example will still have the initial value 0:

Verse

var Example : int = 0
if (not (set Example = ExampleArray[0])) { … }

var Example : int = 0
if (not (set Example = ExampleArray[0])) { … }

You can use not not expression as a way to check if an expression will succeed but make it so the expression never happens.

Outcome of the Expression p	Outcome of the Expression not p	Outcome of the Expression not not p
Succeeds and the result is `p`	The expression fails, and the effects of `p` are not committed. The result of the expression is no value.	The expression succeeds, but the effects of `p` are not committed. The result of the expression is `true`.
Fails and the result is no value	The expression succeeds. The result of the expression is `true`.	The expression fails. The result of the expression is no value.

Reference for the not operator evaluating an expression, represented by p.

And / Or Operators

The decision operator and uses the infix format and is a failable expression that succeeds if both operands succeed, or fails if at least one operand fails.

The decision operator or uses the infix format and is:

A failure context for the first operand.
A failable expression only if the second operand is failable.

The or operator skips evaluation of the second operand if the first operand succeeds.

The table below describes the results of all the operand combinations of success and failure for decision expressions using the operators and and or.

Outcome of the Expression p	Outcome of the Expression q	Outcome of the Expression p and q	Outcome of the Expression p or q
Succeeds and result is `p`	Succeeds and the result is `q`	The expression succeeds, so the effects of both `p` and `q` are committed. The result of the expression is `q`.	The expression succeeds, and only the effects of `p` are committed. `q` is not executed because `p` succeeded. The result of the expression is `p`.
Succeeds and the result is `p`	Fails and the result is no value	The expression fails, and the effects of both `p` and `q` are not committed. The result is no value.	The expression succeeds, and only the effects of `p` are committed. `q` is not executed because `p` succeeded. The result of the expression is `p`.
Fails and the result is no value	Succeeds and the result is `q`	The expression fails, and the effects of both `p` and `q` are not committed. The result is no value.	The expression succeeds, and only the effects of `q` are committed. The result of the expression is `q`.
Fails and the result is no value	Fails and the result is no value	The expression fails, and the effects of both `p` and `q` are not committed. The result is no value.	The expression fails, and the effects of both `p` and `q` are not committed. The result of the expression is no value.

Reference for the and and or operators evaluating expressions, represented by p and q.

Math

With math expressions, you can do the four basic math operations (addition, subtraction, multiplication, and division) with number values, and add strings together. All the operators use the infix format, except + and - can also be a prefix for number values. There are also assign operators, e.g., set X += 10. They are almost the same as doing the operation and then assigning the result, set X = X + 10, the difference is that the X in this case is only evaluated once. The result of an assignment operator is the value used to update the variable.

The table below describes each operator and what types it supports.

Operator	Supported Built-In Types	Description
`+`	`float` `int` `string` `array`	The `+` operator adds two number values together. When used with strings and arrays, the two values are concatenated. You can also use the operator `+` as a prefix to a number, for example `+6`, to help align your code visually, but it won't change the value of the number.
`-`	`float` `int`	The `-` operator subtracts the second number operand from the first operand. You can also use the operator `-` as a prefix to a number to negate the number value, for example `-3.2`.
`*`	`float` `int`	The `*` multiplies two number values together.
`/`	`float` `int` (failable)	The `/` operator divides the first number operand by the second number operand Integer division is failable and returns the `rational` type. For more details on integer division, see int.
`set +=`	`float` `int` `string` `array`	With this operator, you can combine addition and assignment in the same operation to update a variable's value.
`set -=`	`float` `int`	With this operator, you can combine subtraction and assignment in the same operation to update a variable's value.
`set *=`	`float` `int`	With this operator, you can combine multiplication and assignment in the same operation to update a variable's value.
`set /=`	`float`	With this operator, you can combine division and assignment in the same operation to update a variable's value, unless the variable is an integer. For more details on integer division, see int.

Query

Query expressions use the operator ? (query) and check if a logic value is true. Otherwise, the expression fails. The ? (query) operator uses the postfix format.

Outcome of the Expression p	Outcome of the Expression p?
`true`	Succeeds and result is `true`.
`false`	Fails and result is no value.

Reference for the ? (query) operator evaluating expressions, represented by p.

For example: