2.5 Math Flashcards
(14 cards)
Dividing a nonzero floating-point number by zero is undefined in regular arithmetic. Many programming languages produce an error when performing floating-point division by 0, but Coral does not. Coral handles this operation by producing infinity or -infinity, depending on the signs of the operands. Printing a floating-point variable that holds infinity or -infinity outputs Infinity or -Infinity.
If the dividend and divisor in floating-point division are both 0, the division results in a “not a number”. Not a number indicates an unrepresentable or undefined value. Printing a floating-point variable that is not a number outputs NotANumber.
Function
A list of statements executed by invoking the function’s name, with such invoking known as a function call. Any function input values, or arguments, appear within ( ), and are separated by commas if more than one. Below, the function SquareRoot is called with one argument, areaSquare. The function call evaluates to a value, as in SquareRoot(areaSquare) below evaluating to 7.0, which is assigned to sideSquare.
Coral’s Builtin math functions
- SquareRoot(x)
- RaiseToPower(x,y)
- AbsoluteValue(x)
RandomNumber() function
Built-in Coral function that takes two arguments, lowValue and highValue, and returns a random integer in the range lowValue to highValue. Ex: RandomNumber(1, 10) returns a random integer in the range 1 to 10.
SeedRandomNumbers() Function
A programmer can specify the seed using the function SeedRandomNumbers(), as in SeedRandomNumbers(10) or SeedRandomNumbers(99). Note that the seeding should only be done once in a program, before the first call to RandomNumber().
Seed
For the first call to RandomNumber(), no previous random integer exists, so the function uses a built-in integer known as the seed. Coral automatically seeds the pseudo-random number generator with a number based on the current time. Since, the time is different for each program run, the program will get a unique sequence.
pseudo-random
The “pseudo” is because the sequence is the same for the given seed, with the next “random” number computed from the previous one. But the sequence does not repeat itself; millions of numbers can be generated without reaching a repeating pattern within the sequence.
Floating Point Division
Produces integers with fractionals. Will run if at least 1 side of the / is float
Integer Division
Always produces a whole number, does not round, drops fractional
Type conversion
conversion of one data type to another, such as an integer to a float.
implicit conversion
Coral automatically performs several common conversions between integer and float types, and such automatic conversion is known as implicit conversion.
How type conversion works
- For an arithmetic operator like + or *, if either operand is a float, the other is automatically converted to float, and then a floating-point operation is performed.
- For assignments, the right side type is converted to the left side type.
- integer-to-float conversion is straightforward: 25 becomes 25.0.
- float-to-integer conversion just drops the fraction: 4.9 becomes 4.
Type cast
Converts a value of one type to another type. A programmer can type cast an integer to float by multiplying the integer by the float literal 1.0. Ex: If myIntVar is 7, then myIntVar * 1.0 converts integer 7 to float 7.0.
*Another common error is to cast the entire result of integer division, rather than the operands, thus not obtaining the desired floating-point division.
!!!! Review!!!!
modulo operator (%)
Evaluates (division) to the remainder of the division of two integer operands. Ex: 23 % 10 is 3.
Integer only
Examples:
- 9 % 5 is 4. Reason: Since 9 = 5 * 1 + 4, the integer division 9 / 5 results in 1, and the remainder is 4.
- 70 % 7 is 0. Reason: 70 / 7 is 10 with remainder 0.
- 1 % 2 is 1. Reason: 1 / 2 is 0 with remainder 1.
- 10 % 4.0 is not valid. “Remainder” only makes sense for integer operands.
