title: c++之管理数组和字符串
tags:

• 语言工具
  -c++
  categories: c++
  date: 2019-02-19
  thumbnail: https://img.haomeiwen.com/i16271012/4900bfe438f23d6c.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240

数组和字符串

什么是数组

int number [5] = {0}；
char number [5];
int number [5] = {100,12,15,48,6}
int number [5] = {};
int number [5] = {66,55};

int number [3] [3] = {{515,585,84},{},{45,77,24}} 三行三列

const int ARRAY_LENGTH = 5;
int number [ARRAY_LENGTH] = {45,458,48,45,8};
以上即为数组的声明，上面全部是静态数组，即在编译阶段就已经确定了长度。
在执行阶段确定长度的数组为动态数组。

数组的预留空间大小=数组的个数x数组的类型的大小

访问数组中的元素 N [n] 访问的是n+1个元素，超过的补随机数。

务必初始化数组，否则将包含未知数，保证在边界内索引。

使用std::vector初始化动态数组 std::vector<int>dynArray （3）；

C++字符串 使用std::string 初始化字符串、存储用户输入、复制和拼接字符串以及确定字符串长度

应例

0: #include <iostream>
1: #include <string>
2:
3: using namespace std;
5: int main()
6: {
7: string greetString ("Hello std::string!");
8: cout << greetString << endl;
9:
10: cout << "Enter a line of text: " << endl;
11: string firstLine;
12: getline(cin, firstLine);
13:
14: cout << "Enter another: " << endl;
15: string secondLine;
16: getline(cin, secondLine);
17:
18: cout << "Result of concatenation: " << endl;
19: string concatString = firstLine + " " + secondLine;
20: cout << concatString << endl;
21:
22: cout << "Copy of concatenated string: " << endl;
23: string aCopy;
24: aCopy = concatString;
25: cout << aCopy << endl;
26:
27:
cout << "Length of concat string: " << concatString.length() << endl;
28:
29:
return 0;
30: }

image.png

文章依据21天学通C++第八版，纯属小白自学！！！！