PICO-8 Wiki
sgn( [number] )
Returns the sign of a number, 1 for positive, -1 for negative
number
The number to determine the sign of.

Technical Note[]

sgn(0) will return 1, not 0 as might be common on other platforms.

Examples[]

sgn(100) -- returns 1
sgn(0)   -- returns 1 (not 0)
sgn(-14) -- returns -1

See also[]