Question

1. What is the newline character in Java?

2. What is white-space in user input?

3. Answer these questions for each of these Scanner input methods: next(), nextLine(), nextInt(), nextDouble()?

   (a) Does the method skip white-space to ”look” for the next input value? (b) Does the method return a single word or the rest of the line?

   (c) Does the method leave the data on the input stream or consume it? (d) Does the method leave the newline character on the input stream?

   (e) Does the method return the newline character with the input value?

4. What happens if you connect PrintWriter to an existing file? Does it fail, overwrite,

   append?

5. What happens if you do not have write permissions to the file (and path) used to create

   the PrintWriter instance?

Answer 1

NEWLINE CHARACTER IN JAVA

• Newline Character used to move the cursor down to the next line without returning to the beginning of the line.
• It represents the end of a line of a text and beginning of a new line.
• It is represented as a \n escape sequence.
• To write a newline character to a file in java \r\n (return and newline).

The newline character was intended to mean "go to the next line" or "advance the paper in the printer one line" This same character was also called a "Line feed" character on other systems.

WHITE SPACE IN USER INPUT

• White space refers to spaces, tabs and newlines.
• In some places of code it is necessary whereas mostly it is just given to improve readability.
• example : void main() (as they are two different words)

ANSWERS

nextLine() method is used to get the input string that was skipped of the Scanner object.It is used to get the input string that was skipped of the Scanner object.

nextInt() It scans the next token of the input as an Int.

nextDouble() is a method of which is used to scan the next token of the input as a double. If the translation is successful, the scanner past the input that matched.

next() can read the input only till the space.It places the cursor in the same line after reading the input.

Java won't create it by itself since the File class is just a link to an entity that can also not exist at all.

FileNotFoundException - If the given string does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file

Try creating a path for the folder it contains before:

File file = new File("C:/Users/Me/Desktop/directory/file.txt");
file.getParentFile().mkdirs();
PrintWriter printWriter = new PrintWriter(file);