What does scanner.nextLong() do?

What does scanner.nextLong() do?

• A. Reads a float value
• B. Reads a double value
• C. Reads an integer value
• D. Reads a long value

Answer: (D)

Reading a 64-bit integer from input, using the Scanner. This method grabs the next token of input (whitespace-delimited), then parses it as a long, which is Java’s 64-bit signed integer, and returns that value. If the next token isn’t a valid long (for example, it contains letters or a decimal point, or the value is outside the long range), an exception is thrown. It can also throw if there’s no more input or if the scanner is closed. So, this is distinct from methods that read other types: reading a 32-bit int, a 32-bit float, or a 64-bit double would use different methods designed for those types.

Reading a 64-bit integer from input, using the Scanner. This method grabs the next token of input (whitespace-delimited), then parses it as a long, which is Java’s 64-bit signed integer, and returns that value. If the next token isn’t a valid long (for example, it contains letters or a decimal point, or the value is outside the long range), an exception is thrown. It can also throw if there’s no more input or if the scanner is closed.

So, this is distinct from methods that read other types: reading a 32-bit int, a 32-bit float, or a 64-bit double would use different methods designed for those types.