📜  C++字符串

📅  最后修改于: 2020-10-16 07:13:12             🧑  作者: Mango

C++字符串

在C++中, 字符串是std :: 字符串类的对象,它表示字符序列。我们可以对字符串执行许多操作,例如连接,比较,转换等。

C++字符串示例

让我们看一下C++ 字符串的简单示例。

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

输出:

Hello
C++

C++字符串比较示例

让我们看一下使用strcmp()函数进行字符串比较的简单示例。

#include 
#include 
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!!"<

输出:

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

C++字符串Concat示例

让我们看一下使用strcat()函数进行字符串连接的简单示例。

#include 
#include 
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<

输出:

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

C++字符串复制示例

让我们看一下使用strcpy()函数复制字符串的简单示例。

#include 
#include 
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<

输出:

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

C++字符串长度示例

让我们看一下使用strlen()函数查找字符串长度的简单示例。

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

输出:

Length of String = 26

C++字符串函数

Function Description
int compare(const string& str) It is used to compare two string objects.
int length() It is used to find the length of the string.
void swap(string& str) It is used to swap the values of two string objects.
string substr(int pos,int n) It creates a new string object of n characters.
int size() It returns the length of the string in terms of bytes.
void resize(int n) It is used to resize the length of the string up to n characters.
string& replace(int pos,int len,string& str) It replaces portion of the string that begins at character position pos and spans len characters.
string& append(const string& str) It adds new characters at the end of another string object.
char& at(int pos) It is used to access an individual character at specified position pos.
int find(string& str,int pos,int n) It is used to find the string specified in the parameter.
int find_first_of(string& str,int pos,int n) It is used to find the first occurrence of the specified sequence.
int find_first_not_of(string& str,int pos,int n ) It is used to search the string for the first character that does not match with any of the characters specified in the string.
int find_last_of(string& str,int pos,int n) It is used to search the string for the last character of specified sequence.
int find_last_not_of(string& str,int pos) It searches for the last character that does not match with the specified sequence.
string& insert() It inserts a new character before the character indicated by the position pos.
int max_size() It finds the maximum length of the string.
void push_back(char ch) It adds a new character ch at the end of the string.
void pop_back() It removes a last character of the string.
string& assign() It assigns new value to the string.
int copy(string& str) It copies the contents of string into another.
char& back() It returns the reference of last character.
Iterator begin() It returns the reference of first character.
int capacity() It returns the allocated space for the string.
const_iterator cbegin() It points to the first element of the string.
const_iterator cend() It points to the last element of the string.
void clear() It removes all the elements from the string.
const_reverse_iterator crbegin() It points to the last character of the string.
const_char* data() It copies the characters of string into an array.
bool empty() It checks whether the string is empty or not.
string& erase() It removes the characters as specified.
char& front() It returns a reference of the first character.
string&  operator+=() It appends a new character at the end of the string.
string& operator=() It assigns a new value to the string.
char operator[](pos) It retrieves a character at specified position pos.
int rfind() It searches for the last occurrence of the string.
iterator end() It references the last character of the string.
reverse_iterator rend() It points to the first character of the string.
void shrink_to_fit() It reduces the capacity and makes it equal to the size of the string.
char* c_str() It returns pointer to an array that contains null terminated sequence of characters.
const_reverse_iterator crend() It references the first character of the string.
reverse_iterator rbegin() It reference the last character of the string.
void reserve(inr len) It requests a change in capacity.
allocator_type get_allocator(); It returns the allocated object associated with the string.