Classes are something that is mentioned a lot in development and at this point in your development, most of you will not know what classes are and this will get in the way of learning the current content. So here is a brief early introduction before we learn how to create your own classes later in the course.
Classes are a collection of methods that can be tools, methods, etc. All files in the coding part of Java are classes. There are really 2 types of classes: collection classes, and object classes.
Collection classes are often just a collection of similar tools, or functions, that can be used. An example of this type of class would be the math class that contains most of the mathematic functions that can be used in your expressions.
Object classes are classes that define individual objects, their properties, and operations that can be performed on them. For example, you can define a class about vehicles that can be instantiated for each individual vehicle. Each vehicle having their own unique properties and operations, referred to as methods. An example of a method would be: paintVehicle() that would change the colour of one existing vehicle. More on object classes later in the course.
Various mathematical functions are implemented as static methods of the math class. (java.lang)
| Method | Description | Return Type |
|---|---|---|
abs(x) |
Returns the absolute value of x | double|float|int|long |
acos(x) |
Returns the arccosine of x, in radians | double |
asin(x) |
Returns the arcsine of x, in radians | double |
atan(x) |
Returns the arctangent of x as a numeric value between -PI/2 and PI/2 radians | double |
atan2(y,x) |
Returns the angle theta from the conversion of rectangular coordinates (x, y) to polar coordinates (r, theta). | double |
cbrt(x) |
Returns the cube root of x | double |
ceil(x) |
Returns the value of x rounded up to its nearest integer | double |
copySign(x, y) |
Returns the first floating point x with the sign of the second floating point y | double |
cos(x) |
Returns the cosine of x (x is in radians) | double |
cosh(x) |
Returns the hyperbolic cosine of a double value | double |
exp(x) |
Returns the value of Ex | double |
expm1(x) |
Returns ex -1 | double |
floor(x) |
Returns the value of x rounded down to its nearest integer | double |
getExponent(x) |
Returns the unbiased exponent used in x | int |
hypot(x, y) |
Returns sqrt(x2 +y2) without intermediate overflow or underflow | double |
IEEEremainder(x, y) |
Computes the remainder operation on x and y as prescribed by the IEEE 754 standard | double |
log(x) |
Returns the natural logarithm (base E) of x | double |
log10(x) |
Returns the base 10 logarithm of x | double |
log1p(x) |
Returns the natural logarithm (base E) of the sum of x and 1 | double |
max(x, y) |
Returns the number with the highest value | double|float|int|long |
min(x, y) |
Returns the number with the lowest value | double|float|int|long |
nextAfter(x, y) |
Returns the floating point number adjacent to x in the direction of y | double|float |
nextUp(x) |
Returns the floating point value adjacent to x in the direction of positive infinity | double|float |
pow(x, y) |
Returns the value of x to the power of y | double |
random() |
Returns a random number between 0 and 1 | double |
round(x) |
Returns the value of x rounded to its nearest integer | int |
rint(x) |
Returns the double value that is closest to x and equal to a mathematical integer | double |
signum(x) |
Returns the sign of x | double |
sin(x) |
Returns the sine of x (x is in radians) | double |
sinh(x) |
Returns the hyperbolic sine of a double value | double |
sqrt(x) |
Returns the square root of x | double |
tan(x) |
Returns the tangent of an angle | double |
tanh(x) |
Returns the hyperbolic tangent of a double value | double |
toDegrees(x) |
Converts an angle measured in radians to an approx. equivalent angle measured in degrees | double |
toRadians(x) |
Converts an angle measured in degrees to an approx. angle measured in radians | double |
ulp(x) |
Returns the size of the unit of least precision (ulp) of x | double|float |