File Processing Flashcards

1
Q

Files are used for data persistence which is…

A

Permanent retention of data

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2
Q

How do computers store files?

A

Secondary storage devices

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3
Q

What is a file?

A

A sequence of bytes

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4
Q

Files end with

A

End-of-file marker
Or
Specific byte number recorded in data structure

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5
Q

What happens when a file is opened?

A

An object is created with associated stream

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6
Q

Which headers must be included for file processing?

A

<iostream> and <fstream>
</fstream></iostream>

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7
Q

<fstream>'s typedef aliases enables....
</fstream>

A

char output to files

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8
Q

C++ structure on file

A

Not imposed

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9
Q

When an ____________ object is created, a file can be opened for output

A

ofstream

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10
Q

What happens to existing files opened with iOS::out?

A

They are truncated

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11
Q

How can you add to the end of a file?

A

ios::app

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12
Q

ofstream objects must be created while opening a file

A

No, it can be attached later

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13
Q

What does overloaded operator ! do for a stream?

A

Determines if it is opened correctly

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14
Q

What is the failbit for cin?

A

End-of-file indicator

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15
Q

How can you close a stream object?

A

Use close member function or stream object’s destructor

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16
Q

Why do files store data?

A

So it can be received for processing when needed

17
Q

When are objects of ifstream opened for input?

A

By default

18
Q

How do you retrieve data sequentially from a file?

A

Read from the beginning until desired data is found

19
Q

What is the file position pointer for ifstream?

20
Q

What is the file position pointer for ostream?

21
Q

How can you indicate the byte number in a file where next input will occur?

A

get pointer for istream
put pointer for ostream

22
Q

Which three seek directions can seekg indicate?

A

ios::beg
ios::cur
ios::end

23
Q

File position pointer specifies the location as number of bytes from file’s start location or it’s….

24
Q

What member functions return the current locations of the get and put pointers?

A

tellg and tellp

25
Why can you not modify data that is formatted and written to a sequential file?
Record sizes can vary
26
What is an instant access application?
When a particular record must be located immediately
27
What makes instant access to file possible?
random access files
28
How do you format files for random access?
Same size, fixed length records
29
What are the advantages of random access files?
Data can be inserted, updated, or deleted without rewriting the entire file
30
Which ostream member function outputs a fixed number of bytes, beginning at a specific location in memory, to a stream?
write
31
Which istream member function inputs a fixed number of bytes from the specified stream to an area in memory beginning at a specified address specified by get file position pointer?
read
32
How does function write find location to output?
Takes const char* of bytes
33
How to convert a pointer of one type to a pointer of an unrelated type?
reinterpret_cast
34
How can unformatted data be compiled and executed?
Must be on a system compatible with the program that wrote the data
35
Objects of class string do not have uniform size, instead they use....
Dynamically allocated memory