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c语言string转换为int,c语言怎么声明字符串

时间:2023-05-05 20:47:30 阅读:51539 作者:4699

一、int转string

1 .在1.c 11标准中添加了全局函数std:to_string:

stringto_string(intval;

stringto_string(longval;

stringto_string(longlongval;

stringto _ string (未指定val;

stringto _ string (unsigned long val;

stringto _ string (unsignedlonglongval;

stringto _ string (浮动;

stringto _ string (双精度;

stringto_string(longdoubleval;

Example:

//to _ string example # include iostream//STD :3360 cout # include string//STD :3360 string,STD 3: to _ stror STD : string perfect=STD :3360 to _ string (124714 ) is a perfect number ); std:cout pi 'n '; std:cout perfect 'n '; 返回0; }Output:

pi is 3.14159328 is a perfect number2.是使用sstream中定义的字符串流对象实现的

ostringstream os; //制作空的int i=12的内容的输出字符串流的os i; //将int整数I的内容输出到输出字符串流的coutos.str(endl; //使用字符串流的str函数获取流中的内容二、string转int

1 .可以使用1.STD:3360stoi/stol/stoll等函数

Example:

//stoi example # include iostream//STD :3360 cout # include string//STD 33603360 string,std:stoiint main () ) std:string str_迷路的豌豆='-10010110001 '; STD :3360 stringstr _ auto='0x7f '; STD : string :3360 size _ typesz; //aliasofsize _ tint I _ dec=STD :3360 stoi (str _ dec,sz ); inti _ hex=STD :3360 stoi (str _ hex,nullptr,16 ); int i_迷路豌豆=STD:3360stoi(str_迷路豌豆,nullptr,2 ); inti _ auto=STD :3360 stoi (str _ auto,nullptr,0 ); STD :3360 cout str _ dec ' : ' I _ dec ' and [ ' str _ dec.substr (SZ ()n '; STD :3360 cout str _ hex ' : ' I _ hex 'n '; std:cout str_迷路豌豆' : ' i_迷路豌豆'n '; STD :3360 cout str _ auto ' : ' I _ auto 'n '; 返回0; }Output:

2001,A Space Odyssey: 2001 and [,a space odyssey ] 40c :16579-1001100013360-12010 x7f :1272 .采用标准库的atoi函数

字符串s=' 12 '; inta=atoi(s.c_str ) ); 使用sstream头文件中定义的字符串流对象进行转换

istringstreamis('12 ); //构建输入字符串流,并将流的内容初始化为“12”的字符串int i; is i; 从//is流中读取int整数并存储到I中

参考资料:

3358 blog.csdn.net/chavo0/article/details/51038397

3358 blog.csdn.net/na _ beginning/article/details/53576123

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