9.4. Operator Reference

This page documents which type combinations are valid for each operator and what type the result will be. For a conceptual overview of operators, see Expressions.

9.4.1. Arithmetic Operators 

9.4.1.1. Addition (+)

Left \ Right	Int	Long	Float	Double	String
Int	Int	Long	Float	Double	String
Long	Long	Long	Float	Double	String
Float	Float	Float	Float	Double	String
Double	Double	Double	Double	Double	String
String	String	String	String	String	String
Boolean	–	–	–	–	String
Player	–	–	–	–	String
Entity	–	–	–	–	String
Block	–	–	–	–	String
Item	–	–	–	–	String

String concatenation: When either operand is a String, the result is String concatenation. The non-String operand is converted to its textual representation.

@player {{"Score: " + 42}}      # "Score: 42"
@player {{2 + "2"}}             # "22"
@player {{true + " story"}}     # "true story"

9.4.1.3. Multiplication (*)

Left \ Right	Int	Long	Float	Double
Int	Int	Long	Float	Double
Long	Long	Long	Float	Double
Float	Float	Float	Float	Double
Double	Double	Double	Double	Double

Only numeric types support multiplication.

9.4.1.4. Division (/)

Left \ Right	Int	Long	Float	Double
Int	Int	Long	Float	Double
Long	Long	Long	Float	Double
Float	Float	Float	Float	Double
Double	Double	Double	Double	Double

Warning

Integer division: When both operands are Int or Long, division truncates toward zero:

@player {{5 / 2}}      # 2 (not 2.5!)
@player {{5 / 2.0}}    # 2.5
@player {{5 / 2D}}     # 2.5

To get decimal division, ensure at least one operand is Float or Double.

9.4.1.5. Modulo (%)

Returns the remainder after division.

Left \ Right	Int	Long	Float	Double
Int	Int	Long	Float	Double
Long	Long	Long	Float	Double
Float	Float	Float	Float	Double
Double	Double	Double	Double	Double

@player {{5 % 2}}       # 1
@player {{0.5 % 0.2}}   # 0.1

Note that modulo with floating-point types can produce imprecise results due to how floating-point arithmetic works.

Also, modulo with negative numbers follows the same sign rules as Java’s % operator. This means the result has the same sign as the dividend (left operand). For example, (-5) % 2 yields -1 rather than 2.

9.4.2. Comparison Operators 

All comparison operators return Boolean.

9.4.2.1. Equality (==) and Inequality (!=)

	Int	Long	Float	Double	Bool	String	Player	Entity	Block
Int	yes	yes	yes	yes	–	–	–	–	–
Long	yes	yes	yes	yes	–	–	–	–	–
Float	yes	yes	yes	yes	–	–	–	–	–
Double	yes	yes	yes	yes	–	–	–	–	–
Boolean	–	–	–	–	yes	–	–	–	–
String	–	–	–	–	–	yes	–	–	–
Player	–	–	–	–	–	–	yes	–	–
Entity	–	–	–	–	–	–	–	yes	–
Block	–	–	–	–	–	–	–	–	yes

Numeric types can be compared across types.
String comparison is case-sensitive. Use .equalsIgnoreCase() for case-insensitive comparison.
Player/Entity/Block compare by identity (same object).
Item uses == to compare type AND amount.

9.4.2.2. Relational (<, >, <=, >=)

Left \ Right	Int	Long	Float	Double
Int	yes	yes	yes	yes
Long	yes	yes	yes	yes
Float	yes	yes	yes	yes
Double	yes	yes	yes	yes

Only numeric types support relational operators.

9.4.3. Logical Operators 

9.4.3.1. AND (&&)

Returns true only if both operands are true.

Operands	Return Type
Boolean && Boolean	Boolean

@player {{true && true}}    # true
@player {{true && false}}   # false
@player {{false && false}}  # false

Short-circuit: If the left operand is false, the right operand is not evaluated.

# Safe null check which won't throw a NullPointerException
@if player != null && player.isOnline()
    @player You are online!
@fi

9.4.3.2. OR (||)

Returns true if either operand is true.

Operands	Return Type
Boolean \|\| Boolean	Boolean

@player {{true || true}}    # true
@player {{true || false}}   # true
@player {{false || false}}  # false

Short-circuit: If the left operand is true, the right operand is not evaluated.

9.4.3.3. NOT (!)

Prefix unary operator that negates a Boolean.

Operand	Return Type
!Boolean	Boolean

@player {{!true}}   # false
@player {{!false}}  # true

9.4.4. Assignment Operators 

These modify variables in place.

Operator	Equivalent	Description
`x = y`	–	Direct assignment.
`x += y`	`x = x + y`	Add and assign.
`x -= y`	`x = x - y`	Subtract and assign.
`x *= y`	`x = x * y`	Multiply and assign.
`x /= y`	`x = x / y`	Divide and assign.
`x %= y`	`x = x % y`	Modulo and assign.

@define Int score = 10
@var score += 5    # score is now 15
@var score *= 2    # score is now 30
@var score -= 10   # score is now 20