22 KiB
| title | TARGET DECK | FILE TAGS | tags | |
|---|---|---|---|---|
| Strings | Obsidian::STEM | c |
|
Overview
A contiguous sequence of characters terminated by the NUL character (refer to ascii). Text data is said to be more platform-independent than endianness data since it is unaffected by word size or byte ordering.
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Basic
What is a C-style string?
Back: A character array terminated with a NUL character.
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
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Basic
What character terminates all C-style strings?
Back: NUL
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
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Basic
What is the decimal value of NUL in ASCII encoding?
Back: 0
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
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%%ANKI Basic Text is more platform-independent than binary because it is unaffected by what two properties? Back: Word size and byte ordering. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
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printf
The syntax for the format placeholder is %[flags][width][.precision][length]specifier.
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Basic
Which header file contains printf functionality?
Back: stdio.h
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
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Cloze
{1:width} field specifies a {2:minimum} number of characters while {2:precision} specifies a {1:maximum}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
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Cloze
The {width and precision} fields are output related whereas the {length} field is input related.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
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| Flag | Description |
|---|---|
- |
Left-aligns the output |
+ |
Prepends a plus for positive signed-numeric types |
␣ |
Prepends a space for positive signed-numeric types |
0 |
Prepends zeros for numeric types |
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Cloze
The {-} flag {left-aligns the output}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What is the output of printf("%-2d abc", 100)?
Back: 100 abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What is the output of printf("%-4d abc", 100)?
Back: 100 abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
%%ANKI
Basic
What is the output of printf("%.4d abc", 100)?
Back: 0100 abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What is the output of printf("%04d abc", 100)?
Back: 0100 abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What is the output of printf("%.4s abc", "efg")?
Back: efg abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What is the output of printf("%.2s abc", "efg")?
Back: ef abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What is the output of printf("%.2f abc", 0.01234)?
Back: 0.01 abc
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
How does the precision field affect "%s" parameters?
Back: Strings are truncated if longer than the specified precision.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
How does the precision field affect "%f" parameters?
Back: Decimal values are truncated if longer than the specified precision.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What does a negative width field value indicate?
Back: This is actually a positive width with a - (left-align) flag.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
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Basic
The - flag overrides what default behavior?
Back: Output is right-aligned by default.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Cloze
The {+} flag {prepends a plus for positive signed-numeric types}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
%%ANKI
Basic
The + flag overrides what default behavior?
Back: Nothing is prepended to positive signed-numeric types by default.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Cloze
The {␣} flag {prepends a space for positive signed-numeric types}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
The ␣ flag overrides what default behavior?
Back: Nothing is prepended to positive signed-numeric types by default.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
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Basic
How do the + and ␣ flags relate to one another?
Back: Both prepend a character to positive signed-numeric types.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What happens if both the + and ␣ flags are specified?
Back: The + flag takes precedence.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Cloze
The {0} flag {prepends zeros for numeric types}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
What option must be specified for the 0 flag to take effect?
Back: The "width" option.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Basic
The 0 flag overrides what default behavior?
Back: Spaces are used to match the "width" option by default.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
| Length | Description |
|---|---|
hh |
int sized integer argument promoted from a char |
h |
int sized integer argument promoted from a short |
l |
long sized integer argument |
ll |
long long sized integer argument |
z |
size_t sized integer argument |
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Basic
Why do length modifiers for e.g. char exist?
Back: For maximum portability in the face of default argument promotions.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Cloze
The {hh} length corresponds to the {char} type declaration.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Cloze
The {h} length corresponds to the {short} type declaration.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
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Cloze
The {l} length corresponds to the {long} type declaration.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
%%ANKI
Cloze
The {ll} length corresponds to the {long long} type declaration.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
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%%ANKI
Cloze
The {z} length corresponds to the {size_t} type declaration.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
END%%
| Specifier | Description |
|---|---|
d, i |
a decimal signed int |
u |
a decimal unsigned int |
x |
a hexadecimal unsigned int (lowercase) |
X |
a hexadecimal unsigned int (uppercase) |
o |
an octal unsigned int |
s |
a NUL-terminated string |
c |
a char character |
p |
void* address in an implementation-defined format |
%%ANKI
Basic
What character do printf format specifiers start with?
Back: %
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Basic
Why is printf named the way it is?
Back: It stands for print formatted.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%d and %i} format specifers work on a {decimal signed int}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
{%d and %i} are to signed as {%u} is to unsigned.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%u} format specifier outputs a {decimal unsigned int}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
What distinguishes format specifiers %d and %i?
Back: Nothing.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
Which format specifiers were probably used to yield printf output -12?
Back: %d or %i
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
What distinguishes format specifiers %d and %u?
Back: The former is for signed integers, the latter unsigned.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%x} format specifier outputs a {lowercase hexadecimal unsigned int}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
Which format specifier were probably used to yield printf output 7af?
Back: %x
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%X} format specifier outputs an {uppercase hexadecimal unsigned int}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Basic
Which format specifier were probably used to yield printf output 7AF?
Back: %X
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Basic
What distinguishes format specifiers %x and %X?
Back: The former outputs lowercase hex digits, the latter uppercase.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%o} format specifier outputs an {octal unsigned int}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
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Basic
Why doesn't the %o format specifier have a corresponding %O specifier?
Back: There is no distinction between lower and uppercase octal digits.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
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%%ANKI
Cloze
The {%s} format specifiers outputs a {NUL-terminated string}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
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%%ANKI
Basic
Which format specifier was probably used to yield printf output abc?
Back: %s
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%c} format specifier outputs a {char character}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
Which format specifier was probably used to yield printf output a?
Back: %c
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
%%ANKI
Cloze
The {%p} format specifier outputs a {void* address}.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
Which format specifier was probably used to yield printf output 0b80000000?
Back: %p
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
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Basic
How is the address outputted by the %p format specifier written?
Back: In an implementation-specific way.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
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Basic
Given int64_t x, why is printf("%d", x) a problem?
Back: %d matches an int which is not necessarily 64-bits.
Tags: printf
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
END%%
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Basic
What must you use when invoking printf with a fixed-width integer type?
Back: printf-specific macros.
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
Tags: printf
END%%
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Basic
What is PRId32 an example macro for?
Back: A macro that expands to the correct specifier for a 32-bit signed integral type.
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
Tags: printf
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Cloze
{PRId32} is to signed whereas {PRIu32} is to unsigned.
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
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Basic
Which C header specifies printf macros for fixed-width integral types?
Back: <inttypes.h>
Reference: “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.
Tags: printf
END%%
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Basic
Given int32_t x, how might we invoke printf on it?
Back: printf("%" PRId32, x)
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
Tags: printf
END%%
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Basic
What prefix do printf macros from <inttypes.h> share?
Back: PRI
Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
Tags: printf
END%%
References
- Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.
- “Printf,” in Wikipedia, January 18, 2024, https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962.