C declarations were designed so that the **declaration** of an object looks like the use of the object. This isn't quite true - keywords like `volatile` and `const` only exist in declarations - but for the most part, this philosophy can be leveraged to read C declarations.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892098-->
END%%
## Declarations
A **declaration** consists of at least one type-specifier (e.g. `signed short`), storage class (e.g. `static`), and/or type qualifier (e.g. `const`) as well as one or more declarators.
%%ANKI
Basic
How many declarators does a declaration have?
Back: At least one.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892100-->
END%%
%%ANKI
Basic
How many declarations does a declarator have?
Back: N/A.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892101-->
END%%
%%ANKI
Basic
Which part of the following are declarators?
```c
int* a, b;
```
Back: `* a` and `b`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892102-->
END%%
%%ANKI
Basic
Which part of the following are declarations?
```c
int* a, b;
```
Back: The entire line is a single declaration.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892103-->
END%%
%%ANKI
Basic
Which part of the following declaration is the declarator?
```c
const int *const x;
```
Back: `*const x`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892104-->
END%%
%%ANKI
Basic
Which part of the following declaration is the type specifier?
```c
const int *const x;
```
Back: `int`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892105-->
END%%
%%ANKI
Basic
Which part of the following declaration is the type qualifier?
```c
const int *const x;
```
Back: The first `const`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892106-->
END%%
%%ANKI
Basic
What is the type of `x` in the following?
```c
const int *const x, y;
```
Back: `const int* const`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892107-->
END%%
%%ANKI
Basic
What is the type of `y` in the following?
```c
const int *const x, y;
```
Back: `const int`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892108-->
END%%
%%ANKI
Basic
What is the type of `x` in the following?
```c
#define int_ptr int *
int_ptr x, y;
```
Back: `int *`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892109-->
END%%
%%ANKI
Basic
What is the type of `y` in the following?
```c
#define int_ptr int *
int_ptr x, y;
```
Back: `int`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892110-->
END%%
%%ANKI
Basic
What is the type of `x` in the following?
```c
typedef int_ptr int *
int_ptr x, y;
```
Back: `int *`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892111-->
END%%
%%ANKI
Basic
What is the type of `y` in the following?
```c
typedef int_ptr int *
int_ptr x, y;
```
Back: `int *`
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892112-->
END%%
Declarations can be read by complying with the precedence rules outlined below:
1. Find the name of the declaration.
2. Obey the following precedence rules:
1. Parentheses grouping together parts of a declaration
2. Postfix operators `()` and `[]`
3. Prefix operator: the asterisk `*` denoting "pointer to"
3. If `const` and/or `volatile` keyword is next to a type specifier, it applies to the type specifier. Otherwise it applies to the pointer asterisk on its immediate left.
%%ANKI
Basic
In the precedence rules for C declarations, what available postfix operators are there?
Back: `()` and `[]`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892113-->
END%%
%%ANKI
Basic
In the precedence rules for C declarations, what available prefix operators are there?
Back: Just `*`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892114-->
END%%
%%ANKI
Basic
In the precedence rules for C declarations, what available type qualifiers are there?
Back: `const` and `volatile`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892115-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
char *const *(*foo)();
```
Back: A pointer to a function returning a pointer to a `const` pointer-to-char.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892116-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
char *const *foo();
```
Back: A function returning a pointer to a `const` pointer-to-char.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892117-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
int (*(*foo)(void))[3]
```
Back: A pointer to a function (accepting `void`) returning a pointer to an array of `int`s.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892118-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
const int (* volatile foo)[64]
```
Back: A `volatile` pointer to an array of `const int`s.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892119-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
const int * const foo;
```
Back: A `const` pointer to a `const int`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892120-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
const int * foo;
```
Back: A pointer to a `const int`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892121-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
int const * foo;
```
Back: A pointer to a `const int`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892122-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
int * const foo;
```
Back: A `const` pointer-to-int.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892123-->
END%%
%%ANKI
Basic
What is the type of `foo` in the the following declaration?
```c
char *(*foo[10])(int **);
```
Back: An array of pointers to functions (accepting `int **`) returning pointer-to-char.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
<!--ID: 1722786892124-->
END%%
%%ANKI
Basic
What is the type of `signal` in the the following declaration?
```c
void (*signal(int sig, void (*func)(int)))(int);
```
Back: A function (accepting an `int` and `void (*)(int)`) returning a pointer to a function (accepting an `int`) returning `void`.
Reference: Van der Linden, Peter. _Expert C Programming: Deep C Secrets_. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
Fixed width data integral types (e.g. `int32_t`) can be found by including `<stdint.h>`.
%%ANKI
Cloze
The {`<stdint.h>`} header file contains {fixed width data integral types}.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
What does the "width" of an integer type refer to?
Back: The number of bits used to represent its value.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
What two variants does a C integral type declaration have?
Back: Signed and unsigned.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
END%%
%%ANKI
What does it mean for an integer to be "signed"?
Back: It can represent negative, zero, and positive values.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
END%%
%%ANKI
What does it mean for an integer to be "unsigned"?
Back: It can only represent nonnegative values.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
`char`*typically* represents {1} byte(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017164-->
END%%
%%ANKI
Cloze
`short`*typically* represents {2} byte(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017210-->
END%%
%%ANKI
Cloze
`int`*typically* represents {4} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017215-->
END%%
%%ANKI
Cloze
`unsigned`*typically* represents {4} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017219-->
END%%
%%ANKI
Cloze
`long`*typically* represents {8} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
`long long`*typically* represents {8} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708425521263-->
END%%
%%ANKI
Basic
What distinguishes `long` from `long long`?
Back: `long long`s are guaranteed to be at least 64-bit wide.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708425521292-->
END%%
%%ANKI
Basic
*Why* is there both a `long` and `long long`?
Back: `long long`s are at least 64-bit wide, even on 32-bit platforms.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
`char *`*typically* represents {8} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017224-->
END%%
%%ANKI
Cloze
`float`*typically* represents {4} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017227-->
END%%
%%ANKI
Cloze
`double`*typically* represents {8} bytes(s) on a 64-bit platform.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017229-->
END%%
%%ANKI
Basic
Is declaration `int` signed or unsigned?
Back: Signed.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017232-->
END%%
%%ANKI
Basic
How is declaration `unsigned` written more precisely?
Back: `unsigned int`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017234-->
END%%
%%ANKI
Basic
Is declaration `long` signed or unsigned?
Back: Signed.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1707493017239-->
END%%
%%ANKI
Cloze
{1:`float`} has {2:4} byte precision whereas {2:`double`} has {1:8} byte precision.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
The C standard does *not* define {1:upper} bounds on numeric ranges of data types (except for {1:fixed-size} types).
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Negative integer literals are typed in a counterintuitive way. When the compiler sees a number of form `-X`, the type of `X` is determined *before* being negated. Promotion rules are as follows:
How does the compiler process integer literal `-X`?
Back: By first determining the type of `X` and then negating the value.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Back: Depending on value, the resulting type may be `unsigned`.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1710673807995-->
END%%
%%ANKI
Cloze
Octal literals are to {`0`} whereas hexadecimal literals are to {`0x`/`0X`}.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708631820833-->
END%%
%%ANKI
Basic
Which header file contains `INT_MAX`?
Back: `<limits.h>`
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708615249864-->
END%%
%%ANKI
Cloze
{`INT_MAX`} is to `signed` whereas {`UINT_MAX`} is to `unsigned`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708631820837-->
END%%
%%ANKI
Basic
How does `<limits.h>` define `INT_MIN`?
Back: As `(-INT_MAX - 1)`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708631820840-->
END%%
%%ANKI
Basic
*Why* is `INT_MIN` defined as `(-INT_MAX - 1)` instead of directly as e.g. `-2147483648`?
Back: Because `2147483648` (without `-`) would be sized as a non-`int` before being negated.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708631820843-->
END%%
%%ANKI
Cloze
`INT_MAX` is to {`<limits.h>`} whereas `INT32_MAX` is to {`<stdint.h>`}.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708615249873-->
END%%
%%ANKI
Basic
What suffix can be used to denote an `unsigned` integer literal?
Back: Case-insensitive `U`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708615249876-->
END%%
%%ANKI
Basic
What suffix can be used to denote a `long` integer literal?
Back: Case-insensitive `L`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708631820847-->
END%%
%%ANKI
Basic
What suffix can be used to denote a `long long` integer literal?
Back: Case-insensitive `LL`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1708631820850-->
END%%
%%ANKI
Basic
What suffix can be used to denote an `unsigned long long` integer literal?
Back: Case-insensitive `ULL`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1714677608760-->
END%%
%%ANKI
Basic
In what order does C cast "signedness" and size?
Back: C casts size then signedness.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1714677626482-->
END%%
%%ANKI
Basic
Given `short sx`, cast `(unsigned) sx` is more explicitly written as what other sequence of casts?
Back: `(unsigned) (int) sx`
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1714677608762-->
END%%
%%ANKI
Basic
Given `short sx`, are the following two lines equivalent?
```c
(unsigned) sx
(unsigned) (int) sx
```
Back: Yes.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1714677608764-->
END%%
%%ANKI
Basic
Given `short sx`, are the following two lines equivalent?
```c
(unsigned) sx
(unsigned) (unsigned short) sx
```
Back: No.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1714677608766-->
END%%
%%ANKI
Basic
Given `short sx`, why is the following not an identity?
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
<!--ID: 1714677608767-->
END%%
%%ANKI
Basic
What does "signedness" of a variable refer to?
Back: Whether the variable was declared `signed` or `unsigned`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
* Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.
