diff --git a/docs/cpp.html b/docs/cpp.html new file mode 100644 index 00000000..c2ea518c --- /dev/null +++ b/docs/cpp.html @@ -0,0 +1,859 @@ + + + + +C++ 备忘清单 + & cpp cheatsheet & Quick Reference + + + + + + + +

+C++ 备忘清单

+

提供基本语法和方法的 C++ 快速参考备忘单

+

入门

+

hello.cpp

+
#include <iostream>
+int main() {
+    std::cout << "Hello Quick Reference\n";
+    return 0;
+}
+
+

编译运行

+
$ g++ hello.cpp -o hello
+$ ./hello
+Hello Quick Reference
+
+

变量

+
int number = 5;       // 整数
+float f = 0.95;       // 浮点数
+double PI = 3.14159;  // 浮点数
+char yes = 'Y';       // 特点
+std::string s = "ME"; // 字符串（文本）
+bool isRight = true;  // 布尔值
+// 常量
+const float RATE = 0.8;
+
+
+
int age {25};      // 自 C++11
+std::cout << age;  // 打印 25
+
+

原始数据类型

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
数据类型大小范围
int4 bytes-231 到 231-1
float4 bytesN/A
double8 bytesN/A
char1 byte-128 到 127
bool1 bytetrue / false
voidN/AN/A
wchar_t2 到 4 bytes1 个宽字符
+ +

用户输入

+
int num;
+std::cout << "Type a number: ";
+std::cin >> num;
+std::cout << "You entered " << num;
+
+

交换

+
int a = 5, b = 10;
+std::swap(a, b);
+// 输出: a=10, b=5
+std::cout << "a=" << a << ", b=" << b;
+
+

注释

+
// C++中的单行注释
+/* 这是一个多行注释
+    在 C++ 中 */
+
+

If 语句

+
if (a == 10) {
+    // do something
+}
+
+

查看: 条件

+

循环

+
for (int i = 0; i < 10; i++) {
+    std::cout << i << "\n";
+}
+
+

查看: 循环 Loops

+

函数

+ +
#include <iostream>
+ 
+void hello();   // 声明
+ 
+int main() {    // 主函数
+    hello();    // 执行函数
+}
+ 
+void hello() { // 定义
+  std::cout << "Hello Quick Reference!\n";
+}
+
+

查看: 函数 Functions

+

引用

+
int i = 1;
+int& ri = i; // ri 是对 i 的引用
+ri = 2; // i 现在改为 2
+std::cout << "i=" << i;
+i = 3;   // i 现在改为 3
+std::cout << "ri=" << ri;
+
+

ri 和 i 指的是相同的内存位置

+

命名空间

+
#include <iostream>
+namespace ns1 {int val(){return 5;}}
+int main()
+{
+    std::cout << ns1::val();
+}
+
+
+
#include <iostream>
+namespace ns1 {int val(){return 5;}}
+using namespace ns1;
+using namespace std;
+int main()
+{
+    cout << val(); 
+}
+
+

名称空间允许名称下的全局标识符

+

C++ 数组

+

定义

+
std::array<int, 3> marks; // 定义
+marks[0] = 92;
+marks[1] = 97;
+marks[2] = 98;
+// 定义和初始化
+std::array<int, 3> = {92, 97, 98};
+// 有空成员
+std::array<int, 3> marks = {92, 97};
+std::cout << marks[2]; // 输出: 0
+
+

操控

+
┌─────┬─────┬─────┬─────┬─────┬─────┐
+| 92  | 97  | 98  | 99  | 98  | 94  |
+└─────┴─────┴─────┴─────┴─────┴─────┘
+   0     1     2     3     4     5
+
+
+
std::array<int, 6> marks = {
+  92, 97, 98, 99, 98, 94
+};
+// 打印第一个元素
+std::cout << marks[0];
+// 将第 2 个元素更改为 99
+marks[1] = 99;
+// 从用户那里获取输入
+std::cin >> marks[2];
+
+

展示

+
char ref[5] = {'R', 'e', 'f'};
+// 基于范围的for循环
+for (const int &n : ref) {
+    std::cout << std::string(1, n);
+}
+// 传统的for循环
+for (int i = 0; i < sizeof(ref); ++i) {
+    std::cout << ref[i];
+}
+
+

多维

+
     j0   j1   j2   j3   j4   j5
+   ┌────┬────┬────┬────┬────┬────┐
+i0 | 1  | 2  | 3  | 4  | 5  | 6  |
+   ├────┼────┼────┼────┼────┼────┤
+i1 | 6  | 5  | 4  | 3  | 2  | 1  |
+   └────┴────┴────┴────┴────┴────┘
+
+
+
int x[2][6] = {
+    {1,2,3,4,5,6}, {6,5,4,3,2,1}
+};
+for (int i = 0; i < 2; ++i) {
+    for (int j = 0; j < 6; ++j) {
+        std::cout << x[i][j] << " ";
+    }
+}
+// 输出: 1 2 3 4 5 6 6 5 4 3 2 1 
+
+

C++ 条件

+

If Clause

+
if (a == 10) {
+    // do something
+}
+
+
+
int number = 16;
+if (number % 2 == 0)
+{
+    std::cout << "even";
+}
+else
+{
+    std::cout << "odd";
+}
+// 输出: even
+
+

Else if 语句

+
int score = 99;
+if (score == 100) {
+    std::cout << "Superb";
+}
+else if (score >= 90) {
+    std::cout << "Excellent";
+}
+else if (score >= 80) {
+    std::cout << "Very Good";
+}
+else if (score >= 70) {
+    std::cout << "Good";
+}
+else if (score >= 60)
+    std::cout << "OK";
+else
+    std::cout << "What?";
+
+

运算符

+ +

关系运算符

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
:----
a == ba 等于 b
a != ba 不等于 b
a < ba 小于 b
a > ba 大于 b
a <= ba 小于或等于 b
a >= ba 大于或等于 b
+

赋值运算符

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
范例相当于
a += bAka a = a + b
a -= bAka a = a - b
a *= bAka a = a * b
a /= bAka a = a / b
a %= bAka a = a % b
+

逻辑运算符

+ + + + + + + + + + + + + + + + + + + + + +
ExampleMeaning
exp1 && exp2Both are true (AND)
`exp1
!expexp is false (NOT)
+

位运算符

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
OperatorDescription
a & bBinary AND
`ab`
a ^ bBinary XOR
a ~ bBinary One's Complement
a << bBinary Shift Left
a >> bBinary Shift Right
+

三元运算符

+
           ┌── True ──┐
+Result = Condition ? Exp1 : Exp2;
+           └───── False ─────┘
+
+
+
int x = 3, y = 5, max;
+max = (x > y) ? x : y;
+// 输出: 5
+std::cout << max << std::endl;
+
+
+
int x = 3, y = 5, max;
+if (x > y) {
+    max = x;
+} else {
+    max = y;
+}
+// 输出: 5
+std::cout << max << std::endl;
+
+

switch 语句

+
int num = 2;
+switch (num) {
+    case 0:
+        std::cout << "Zero";
+        break;
+    case 1:
+        std::cout << "One";
+        break;
+    case 2:
+        std::cout << "Two";
+        break;
+    case 3:
+        std::cout << "Three";
+        break;
+    default:
+        std::cout << "What?";
+        break;
+}
+
+

C++ 循环

+

While

+
int i = 0;
+while (i < 6) {
+    std::cout << i++;
+}
+// 输出: 012345
+
+

Do-while

+
int i = 1;
+do {
+    std::cout << i++;
+} while (i <= 5);
+// 输出: 12345
+
+

Continue 语句

+
for (int i = 0; i < 10; i++) {
+    if (i % 2 == 0) {
+        continue;
+    }
+    std::cout << i;
+} // 输出: 13579
+
+

无限循环

+
while (true) { // true or 1
+    std::cout << "无限循环";
+}
+
+
+
for (;;) {
+    std::cout << "无限循环";
+}
+
+
+
for(int i = 1; i > 0; i++) {
+    std::cout << "infinite loop";
+}
+
+

for_each (C++11 起)

+
#include <iostream>
+int main()
+{
+    auto print = [](int num) {
+      std::cout << num << std::endl;
+    };
+    std::array<int, 4> arr = {1, 2, 3, 4};
+    std::for_each(arr.begin(), arr.end(), print);
+    return 0;
+}
+
+ +

基于范围 (C++11 起)

+
for (int n : {1, 2, 3, 4, 5}) {
+    std::cout << n << " ";
+}
+// 输出: 1 2 3 4 5
+
+
+
std::string hello = "Quick Reference.ME";
+for (char c: hello)
+{
+    std::cout << c << " ";
+}
+// 输出: Q u i c k R e f . M E 
+
+

中断语句

+
int password, times = 0;
+while (password != 1234) {
+    if (times++ >= 3) {
+        std::cout << "Locked!\n";
+        break;
+    }
+    std::cout << "Password: ";
+    std::cin >> password; // input
+}
+
+

Several variations

+
for (int i = 0, j = 2; i < 3; i++, j--){
+    std::cout << "i=" << i << ",";
+    std::cout << "j=" << j << ";";
+}
+// 输出: i=0,j=2;i=1,j=1;i=2,j=0;
+
+

C++ 函数

+

参数和返回

+
#include <iostream>
+int add(int a, int b) {
+    return a + b;  
+}
+int main() {
+    std::cout << add(10, 20); 
+}
+
+

add 是一个接受 2 个整数并返回整数的函数

+

重载

+
void fun(string a, string b) {
+    std::cout << a + " " + b;
+}
+void fun(string a) {
+    std::cout << a;
+}
+void fun(int a) {
+    std::cout << a;
+}
+
+

内置函数

+
#include <iostream>
+#include <cmath> // 导入库
+ 
+int main() {
+    // sqrt() 来自 cmath
+    std::cout << sqrt(9);
+}
+
+

C++ 预处理器

+

预处理器

+ + + +

Includes

+
#include "iostream"
+#include <iostream>
+
+

Defines

+
#define FOO
+#define FOO "hello"
+#undef FOO
+
+

If

+ +
#ifdef DEBUG
+  console.log('hi');
+#elif defined VERBOSE
+  ...
+#else
+  ...
+#endif
+
+

Error

+
#if VERSION == 2.0
+  #error Unsupported
+  #warning Not really supported
+#endif
+
+

宏

+
#define DEG(x) ((x) * 57.29)
+
+

令牌连接

+
#define DST(name) name##_s name##_t
+DST(object);   #=> object_s object_t;
+
+

字符串化

+
#define STR(name) #name
+char * a = STR(object);   #=> char * a = "object";
+
+ +

文件和行

+
#define LOG(msg) console.log(__FILE__, __LINE__, msg)
+#=> console.log("file.txt", 3, "hey")
+
+ +

各种各样的

+

转义序列

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
转义序列说明
\b退格键
\f换页
\n新队
\r返回
\t水平制表符
\v垂直制表符
\\反斜杠
\'单引号
\"双引号
\?问号
\0空字符
+

关键字

+ + + +

预处理器

+ + +

另见

+ +
+ diff --git a/docs/npm.html b/docs/npm.html index f9350d06..30e190a9 100644 --- a/docs/npm.html +++ b/docs/npm.html @@ -550,7 +550,7 @@