UKismetMathLibrary::SignOfFloat

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticBlueprintPureUFUNCTION

Description

Returns -1.0 if A is negative, 0.0 if A is exactly zero, and +1.0 if A is positive.

Caveats & Gotchas

• Returns exactly 0.0 for A == 0.0, unlike FMath::Sign which returns +1 for zero in some engine versions. Verify the expected zero behavior when porting between these two.
• Returns a double (not int), so comparing the result with == to integer literals in C++ requires care. Blueprint pins it as float, which may cause a silent precision narrowing.

Signature

static UE_INL_API double SignOfFloat(double A);

Parameters

Name	Type	Description	Default
A	double	The value whose sign to evaluate.	—

Return Type

double

Example

Apply a force in the direction of a velocity component C++

double VelocityX = -42.5;
double Direction = UKismetMathLibrary::SignOfFloat(VelocityX); // returns -1.0
FVector Force = FVector(Direction * ForceMagnitude, 0.0, 0.0);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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