C++中string、char、const char 相互转化

浅浅的花香味﹌ 2023-09-26 20:43 141阅读 0赞

## 目录  ##

*  string转const char \*
 *  string转char \* 
 *  char \*转string 
 *  const char \*转string 
 *  const char \*转char \*
 *  char \*转const char \*

## string转const char \* ##

/*
    	string转const char * 
    */
    #include<iostream>
    #include<string>
    using namespace std;
    
    
    int main() {
        
    	string str = "hello world!";
    	const char *p = str.c_str();
    	cout << p << endl;
    	return 0;
    }

## string转char \*  ##

/*
    	string转char * 
    */
    #include<iostream>
    #include<string>
    using namespace std;
    
    int main() {
        
    	string str="hello world!";
    	char *p;
    	int len = str.length();
    	p=(char *)malloc((len+1)*sizeof(char));
    	str.copy(p,len,0);	// 0代表从头开始，len是复制字符个数
    	cout << p << endl;
    	return 0; 
    }

## char \*转string  ##

/*
    	char *转string 
    */
    #include<iostream>
    #include<string>
    using namespace std;
    int main() {
        
    	char *p = "hello world!";
    	string str(p);  // 方法1 
    	// 方法2： string str;  str = p;
    	cout << str << endl;
    	return 0;
    }

## const char \*转string  ##

/*
    	const char *转string 
    */
    #include<iostream>
    #include<string>
    using namespace std;
    int main() {
        
    	const char *p = "hello world!";
    	string str(p);  // 方法1 
    	// 方法2： string str;  str = p;
    	cout << str << endl;
    	return 0;
    }

## const char \*转char \*  ##

/*
    	const char *转char *
    */
    #include<iostream>
    #include<string>
    using namespace std;
    int main() {
        
    	const char *p = "hello world!";
    	char *s = (char *)p;
    	cout << s << endl;
    	return 0;
    }

## char \*转const char \*  ##

/*
    	char *转const char *
    */
    #include<iostream>
    #include<string>
    using namespace std;
    int main() {
        
    	char *p = "hello world!";
    	const char *s = (const char*)p;
    	cout << s << endl;
    	return 0;
    }