Difference between revisions of "Category:C"

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(Created page with "== Language == * [https://en.wikipedia.org/wiki/Operators_in_C_and_C%2B%2B Operators in C] == Compiler == * Linux GCC * HI-TECH PICC for PIC === Declaration === * [http://en....")
 
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== Operations ==
 
=== Relations ===
 
* == 检查两个操作数的值是否相等,如果相等则条件为真。 (A == B) 不为真。
 
* != 检查两个操作数的值是否相等,如果不相等则条件为真。 (A != B) 为真。
 
* > 检查左操作数的值是否大于右操作数的值,如果是则条件为真。 (A > B) 不为真。
 
* < 检查左操作数的值是否小于右操作数的值,如果是则条件为真。 (A < B) 为真。
 
* >= 检查左操作数的值是否大于或等于右操作数的值,如果是则条件为真。 (A >= B) 不为真。
 
* <= 检查左操作数的值是否小于或等于右操作数的值,如果是则条件为真。 (A <= B) 为真。
 
=== Logic Operations ===
 
* && 称为逻辑与运算符。如果两个操作数都非零,则条件为真。 (A && B) 为假。
 
* || 称为逻辑或运算符。如果两个操作数中有任意一个非零,则条件为真。 (A || B) 为真。
 
* ! 称为逻辑非运算符。用来逆转操作数的逻辑状态。如果条件为真则逻辑非运算符将使其为假。 !(A && B) 为真。
 
=== Bit Opeartions ===
 
* & 如果同时存在于两个操作数中,二进制 AND 运算符复制一位到结果中。 (A & B) 将得到 12,即为 0000 1100
 
* | 如果存在于任一操作数中,二进制 OR 运算符复制一位到结果中。 (A | B) 将得到 61,即为 0011 1101
 
* ^ 如果存在于其中一个操作数中但不同时存在于两个操作数中,二进制异或运算符复制一位到结果中。 (A ^ B) 将得到 49,即为 0011 0001
 
* ~ 二进制补码运算符是一元运算符,具有"翻转"位效果,即0变成1,1变成0。 (~A ) 将得到 -61,即为 1100 0011,一个有符号二进制数的补码形式。
 
* << 二进制左移运算符。左操作数的值向左移动右操作数指定的位数。 A << 2 将得到 240,即为 1111 0000
 
* >> 二进制右移运算符。左操作数的值向右移动右操作数指定的位数。 A >> 2 将得到 15,即为 0000 1111
 
=== Assignment Operations ===
 
* = 简单的赋值运算符,把右边操作数的值赋给左边操作数 C = A + B 将把 A + B 的值赋给 C
 
* += 加且赋值运算符,把右边操作数加上左边操作数的结果赋值给左边操作数 C += A 相当于 C = C + A
 
* -= 减且赋值运算符,把左边操作数减去右边操作数的结果赋值给左边操作数 C -= A 相当于 C = C - A
 
* *= 乘且赋值运算符,把右边操作数乘以左边操作数的结果赋值给左边操作数 C *= A 相当于 C = C * A
 
* /= 除且赋值运算符,把左边操作数除以右边操作数的结果赋值给左边操作数 C /= A 相当于 C = C / A
 
* %= 求模且赋值运算符,求两个操作数的模赋值给左边操作数 C %= A 相当于 C = C % A
 
* <<= 左移且赋值运算符 C <<= 2 等同于 C = C << 2
 
* >>= 右移且赋值运算符 C >>= 2 等同于 C = C >> 2
 
* &= 按位与且赋值运算符 C &= 2 等同于 C = C & 2
 
* ^= 按位异或且赋值运算符 C ^= 2 等同于 C = C ^ 2
 
* |= 按位或且赋值运算符 C |= 2 等同于 C = C | 2
 
=== MISC ===
 
* sizeof() 返回变量的大小。 sizeof(a) 将返回 4,其中 a 是整数。
 
* & 返回变量的地址。 &a; 将给出变量的实际地址。
 
* * 指向一个变量。 *a; 将指向一个变量。
 
* ? : 条件表达式 如果条件为真 ? 则值为 X : 否则值为 Y
 
  
 
== Header file Definition ==
 
== Header file Definition ==

Latest revision as of 13:19, 8 November 2019

Language

Compiler

  • Linux GCC
  • HI-TECH PICC for PIC

Declaration

Data type

Classic basic primitive types may include:

  • Character (character, char);
  • Integer (integer, int, short, long, byte) with a variety of precisions;
  • Floating-point number (float, double, real, double precision);
  • Fixed-point number (fixed) with a variety of precisions and a programmer-selected scale.
  • Boolean, logical values true and false.
  • Reference (also called a pointer or handle), a small value referring to another object's address in memory, possibly a much larger one.

More sophisticated types which can be built-in include:

  • Tuple in Standard ML, Python, Scala
  • List in Common Lisp, Scheme, Haskell
  • Complex number in C99, Fortran, Common Lisp, Python, D, Go
  • Rational number in Common Lisp, Haskell
  • Associative array in Perl, Python, Ruby, Javascript, Lua, D, Go
  • First-class function, in all functional languages, Javascript, Lua, D, Go, and in newer standards of C++, Java, C#, Perl
type width default signed range unsigned range
bool 1 bit unsigned - 0, 1
char 8 bits, 1 byte signed -128 to +127 0 to +255
short 16 bits, 2 bytes signed -32,768 to +32,767 0 to +65,535
int 16 bits, 2 bytes signed -32,768 to +32,767 0 to +65,535
long 32 bits, 4 bytes signed -2,147,483,648 to +2,147,483,647 0 to +4,294,967,295
float 4 bytes IEEE 754 signed 1.175494351E-38 to 3.402823466E+38
pointer 1, 2, 3 or 4 bytes generic


Easy to remember integer data types :

data type width signed/
unsigned
range
s8 8 bits (1 byte) signed -128 to +127
s16 16 bits (2 bytes) signed -32,768 to +32,767
s32 32 bits (4 bytes) signed -2,147,483,648 to +2,147,483,647
s64* 64 bits (8 bytes) signed −9,223,372,036,854,775,808
to 9,223,372,036,854,775,807
u8 8 bits (1 byte) unsigned 0 to +255
u16 16 bits (2 bytes) unsigned 0 to +65,535
u32 32 bits (4 bytes) unsigned 0 to +4,294,967,295
u64* 64 bits (8 bytes) unsigned 0 to +18,446,744,073,709,551,615

Data Format

From to function example description reference
String char toCharArray sensorVal.toCharArray(sensorPrintout, 4); TFT
float string dtostrf dtostrf(f_volt, 6, 2, volt_char); f_volt is float value
Example Example Example
  • printf
  • String aaa = String(bbb) // bbb is char array

Data Type

- - -
Byte 8 bit Example
Int Example Example
Char Example Example
Hex Example Example

Header file Definition

Define macro

For examples set pins for segment display, file seg.h

  • Further refer to SFR_Macro.h in BSP of nuvoton
#define set_a      P05 = 1
#define set_b      P03 = 1
#define set_c      P10 = 1
#define set_d      P01 = 1
#define set_e      P07 = 1
#define set_f      P02 = 1
#define set_g      P14 = 1
#define set_dot    P00 = 1

Define type

typedef bit                   BIT;
typedef unsigned char         UINT8;
typedef unsigned int          UINT16;
typedef unsigned long         UINT32;

typedef unsigned char         uint8_t;
typedef unsigned int          uint16_t;
typedef unsigned long         uint32_t;

Complier

Common Header

Subcategories

This category has only the following subcategory.

Pages in category "C"

The following 2 pages are in this category, out of 2 total.