QUESTION 14:
What do you expect is the output of the following program fragment:
int x = 9; System.out.println( Math.sqrt( x ) );
Inspect the documentation.
What is the type of the argument expected by sqrt()?
double
What is the type of value returned by sqrt()?
double
Is sqrt() a static method?
Yes
If you look further at
the documentation
for sqrt() you find some details:
Returns the correctly rounded positive square root of a double value. If the argument is NaN or less than zero, the result is NaN.
NaN stands for "Not a Number".
This is a 64-bit pattern that is returned by sqrt()
when its argument is not correct.
Here is an example run of the program:
C:\chap11>java SquareRoot Enter a double: -3 square root : NaN
Here the method returned the 64-bit pattern NaN.
The println() method writes
the characters "NaN" when it sees this pattern.
(The actual bit pattern is not character data.)
In a highly secure, industrial-strength programming language like Java, the behavior of a function must be described for all possible input, both in range and out of range. The documentation describes all of these cases.
What do you expect is the output of the following program fragment:
int x = 9; System.out.println( Math.sqrt( x ) );