Roll 4 and 6 is 10
Roll 3 and 1 is 4
Roll 1 and 6 is 7
Do not use Math.random(). Use new to create a
Random object, and use its nextInt method
to generate the random numbers.
Make sure you simulate two separate rolls instead of trying to use a single
random call. (It matters
if you're on Ventnor, and little brother has a hotel on Boardwalk.)
Java Random class.
Write a program RandomLet.java
to read a line of text, choose a single character at
random, remove it from the string, then print the removed character (surrounded
by tic marks), its
previous position in the string, and the line without it.
Like this:
Enter a line of text: This is a line of text.
Removed 's' at position 6. String is now:
This i a line of text.
Enter a line of text: This is a line of text.
Removed 'o' at position 15. String is now:
This is a line f text.
Enter a line of text: This is not really a line of text, it's only faking.
Removed 'e' at position 30. String is now:
This is not really a line of txt, it's only faking.
Note that the assignment chooses a letter in the string, and removes that
single occurrence. If the letter is repeated, only the chosen one is
removed. See the first example above, where the program removes the s at
position 6, but does not remove the other s at position 3.
Java String has no method to erase a single character. You will want to form the result by concatenating two substrings: The portion before the deletion, and the portion afterwards.
Write a program BuildingHeight.java
to estimate the height of a distant building. Input
the distance, and the elevation angle of the line of sight to the top of
the building, in degrees. Looks like this:
How far is the building (meters)? 100
What is the elevation angle of the top? 22.5
The building is 41.4213562373095 meters high.
How far is the building (meters)? 500
What is the elevation angle of the top? 17.6
The building is 158.60934279317013 meters high.
How far is the building (meters)? 66.5
What is the elevation angle of the top? 20
The building is 24.204020578702455 meters high.
If your trig is little rusty, this is a straightforward triangle
problem. The height is just the product of the distance and
the tangent of the elevation angle. Happily, Java's Math
class provides a tangent function that will do the trick.
Unfortunately, it wants its argument in radians instead of
degrees, but, of course,
you just have to multiply the degrees by π over 180. So, this:
height=distance×tan
Java's Math object has all the bits you need, including
the tangent function and the value of π. All values should be doubles.(
elevation×π
180
)