Question

programming with data files

public class scannerstuff
{
public static void main(string args)
{
try
{
scanner input = new scanner(new file(\shape.txt\));
while (input.hasnext())
{
int num = / missing code a /;
string color = / missing code b /;
double area = / missing code c /;
system.out.println(num + \ \ + color + \ \ + area);
}
}
catch(ioexception e)
{
system.out.println();
}
}
}

option 1:
a: input.next()
b: input.next()
c: input.next()

option 2:
a: input.nextint()
b: next(input)
c: input.nextint()

option 3:
a: input.nextint()
b: input.next()
c: input.nextdouble()

Explanation:

🆕 New Concept Discovered: Java Scanner Token Parsing
Reading specific data types from a file stream.

Step 1: Analyze the Variable Types

We need to find the correct Java Scanner methods to read values into three variables with different data types:

1. int num = / missing code A /; -> Requires an integer reading method.
2. String color = / missing code B /; -> Requires a text/string reading method.
3. double area = / missing code C /; -> Requires a floating-point decimal reading method.

Step 2: Match Variables to Scanner Methods

• For num (int): The standard Scanner method to read the next token as an integer is input.nextInt().
• For color (String): The standard Scanner method to read the next token as a string is input.next().
• For area (double): The standard Scanner method to read the next token as a double-precision floating-point number is input.nextDouble().

Step 3: Evaluate the Options

• Option 1:
• A: input.next() (Incorrect: returns a String, cannot be directly assigned to an int without parsing).
• Option 2:
• B: next(input) (Incorrect syntax: next() is an instance method called on the scanner object, not a static method taking the scanner as an argument).
• Option 3:
• A: input.nextInt() (Correct for int)
• B: input.next() (Correct for String)
• C: input.nextDouble() (Correct for double)

Answer:

Option 3