C++字串

在C++中，字串(string)是一個表示字元序列的std::string類的對象。可以對字串執行許多操作，如：串聯，比較，轉換等。

C++字串示例

下麵來看看看C++字串的簡單例子。

#include <iostream>
using namespace std;
int main( ) {
    string s1 = "Hello";
        char ch[] = { 'C', '+', '+'};
        string s2 = string(ch);
        cout<<s1<<endl;
        cout<<s2<<endl;
}

執行上面示例代碼得到如下結果 -

Hello
C++

C++字串比較示例

下麵來看看看使用strcmp()函數的字串比較的簡單例子。

#include <iostream>
#include <cstring>
using namespace std;
int main ()
{
  char key[] = "mango";
  char buffer[50];
  do {
     cout<<"What is my favourite fruit? ";
     cin>>buffer;
  } while (strcmp (key,buffer) != 0);
 cout<<"Answer is correct!!"<<endl;
  return 0;
}

執行上面示例代碼得到如下結果 -

What is my favourite fruit? apple
What is my favourite fruit? banana
What is my favourite fruit? mango
Answer is correct!!

C++字串Concat示例

下麵來看看看使用strcat()函數的字串連接的簡單示例。

#include <iostream>
#include <cstring>
using namespace std;
int main()
{
    char key[25], buffer[25];
    cout << "Enter the key string: ";
    cin.getline(key, 25);
    cout << "Enter the buffer string: ";
     cin.getline(buffer, 25);
    strcat(key, buffer);
    cout << "Key = " << key << endl;
    cout << "Buffer = " << buffer<<endl;
    return 0;
}

執行上面示例代碼得到如下結果 -

Enter the key string: Welcome to
Enter the buffer string:  C++ Programming.
Key = Welcome to C++ Programming.
Buffer =  C++ Programming.

C++字串複製示例

下麵來看看看使用strcpy()函數複製字串的簡單示例。

#include <iostream>
#include <cstring>
using namespace std;
int main()
{
    char key[25], buffer[25];
    cout << "Enter the key string: ";
    cin.getline(key, 25);
    strcpy(buffer, key);
    cout << "Key = "<< key << endl;
    cout << "Buffer = "<< buffer<<endl;
    return 0;
}

執行上面示例代碼得到如下結果 -

Enter the key string: C++ Tutorial
Key = C++ Tutorial
Buffer = C++ Tutorial

C++字串長度示例

下麵來看看看使用strlen()函數計算字串長度的簡單示例。

#include <iostream>
#include <cstring>
using namespace std;
int main()
{
    char ary[] = "Welcome to C++ Programming";
    cout << "Length of String = " << strlen(ary)<<endl;
    return 0;
}

執行上面示例代碼得到如下結果 -

Length of String = 26