- If[ <Condition>, <Object> ]
- Yields a copy of the object if the condition evaluates to true, and an undefined object if it evaluates to false.
- If[ <Condition>, <Object a>, <Object b> ]
- Yields a copy of object a if the condition evaluates to true, and a copy of object b if it evaluates to false.
|Warning:||Both objects must be of the same type.|
The If command can be used to create conditional functions. Such conditional functions may be used as arguments in any command that takes a function argument, such as Derivative, Integral, and Intersect.
f(x) = If[x < 3, sin(x), x^2]yields a piecewise function that equals sin(x) for x < 3 and x2 for x ≥ 3.
f(x) = If[0 <= x <= 3, sin(x) ]yields a function that equals sin(x) for x between 0 and 3 (and undefined otherwise).
If Command in Scripting
If command can be used in scripts to perform different actions under certain conditions.
If[Mod[n, 7] == 0, SetCoords[A, n, 0], SetCoords[A, n, 1]]modifies the coordinates of point A according to the given condition. In this case it would be easier to use
SetCoords[A, n, If[Mod[n, 7] == 0,0,1]].
Note that arguments of If must be Objects or Scripting Commands, not assignments. Syntax
b=If[a>1,2,3] is correct, but b=2 or b=3 would not be accepted as parameters of If.