Return the absolute value of {expr}. When {expr} evaluates to a |Float| abs() returns a |Float|. When {expr} can be converted to a |Number| abs() returns a |Number|. Otherwise abs() gives an error message and returns -1. Examples: echo abs(1.456) 1.456 echo abs(-5.456) 5.456 echo abs(-4) 4 Can also be used as a |method|: Compute()->abs() {only available when compiled with the |+float| feature}