Homework Help: Questions and Answers: Assuming that (scan) is a properly initialized scanner variable, which of the following correctly inputs a double?
A. double val = scan.nextLine();
B. double val = scan.nextDouble();
C. double val = nextDouble();
D. double val = scan.nextValue();
E. double val = scan.nextpouble;
Answer:
First, let’s understand the questions: It’s about to determine the correct way to input a double value using a Scanner object.
Given Options: Step by Step Answering
a) double val = scan.nextLine();
nextLine()
reads an entire line of input as aString
, not as adouble
.- This is incorrect because it will not convert the input to a
double
.
b) double val = scan.nextDouble();
nextDouble()
is the correct method in theScanner
class to read the next input as adouble
directly.- This is correct because this method reads and converts the input into a
double
.
c) double val = nextDouble();
- This calls
nextDouble()
without specifying thescan
object (which is the Scanner instance). - This is incorrect because it doesn’t reference the scanner object.
d) double val = scan.nextValue();
- There is no method called
nextValue()
in theScanner
class. - This is incorrect because this method doesn’t exist.
e) double val = scan.nextpouble;
- This has a typo. There is no method
nextpouble()
. - This is incorrect due to the syntax error.
Final Answer
Based on the above analysis, the correct answer is:
b) double val = scan.nextDouble();
This method call will read the next token from the input as a double value.
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