constrain(x, a, b)

Constrains a number to be within a range.

x: the number to constrain, all data types

a: the lower end of the range, all data types

b: the upper end of the range, all data types

x: if x is between a and b

a: if x is less than a

b: if x is greater than b

sensVal = constrain(sensVal, 10, 150);
// limits range of sensor values to between 10 and 150 

* min(x, y) * max(x, y)

Source: arduino.cc