本文整理了C++中String-to-Int的10种方式,并对其性能进行了对比。 这些方式包含: atoi strtol sscanf sstream lexical_cast stoi from_chars spanstream constexpr from_chars simple compile time to_int 这个列表是按时间排序的,从C89到C++23。 据群内小调查
CPP(c++解法) #include <cmath> using namespace std; class DigPow { public: static int digPow(int n, int p){ long long sum=0; for(char digit : to_string(n)){ sum+=pow(digit-'0',p++); } return (sum/n)*n==sum ? sum/n : -1; } }; #include <string> #include <cmath...
If no valid conversion could be performed, a zero value is returned. If the correct value is out of the range of representable values, INT_MAX (2147483647) or INT_MIN (-2147483648) is returned. 代码: classSolution {public:intmyAtoi(stringstr) {constsize_t len =str.length();//index of...
// C++ program to demonstrate the// use of a stringstream to// convert string to int#include<iostream>#include<sstream>usingnamespacestd;// Driver codeintmain(){strings ="12345";// object from the class stringstreamstringstreamgeek;// inserting string s in geek streamgeek << s;// The ob...
这里使用functon template的方式将std::string转int、std::string转double。 stringstream_to_double.cpp / C++ 1 /* 2 (C) OOMusou 2006http://oomusou.cnblogs.com 3 4 Filename : stringstream_to_double.cpp 5 Compiler : Visual C++ 8.0
Example 1: C++ string to int Using stoi() #include<iostream>#include<string>intmain(){std::stringstr ="123";intnum;// using stoi() to store the value of str1 to xnum =std::stoi(str);std::cout<< num;return0; } Run Code ...
要将std::string转换为int,您可以使用C++标准库中的std::stoi函数。以下是如何使用std::stoi函数的示例代码: ```cpp #include<iostream> #in...
#include"iostream"using namespace std;#include"string"intmain(){string s1="Tom And Jerry, Hello World, Tom !";// 删除从 0 位置开始的 3 个字符// 然后在 0 位置处插入 Jack 字符串// 返回的索引仍然是字符串本身string s2=s1.replace(0,3,"Jack");// 打印 s1 和 返回的字符串cout<<"s1...
intatoi(constchar*str); *stris a pointer to a string to be converted to an integer. atoi()Example Codes #include<stdio.h>#include<stdlib.h>intmain(void){intvalue;charstr[20];strcpy(str,"123");value=atoi(str);printf("String value = %s, Int value = %d\n",str,value);return(0)...
CPP(c++解法) #include <cmath> usingnamespacestd; classDigPow { public: staticintdigPow(intn,intp){ longlongsum=0; for(chardigit:to_string(n)){ sum+=pow(digit-'0',p++); } return(sum/n)*n==sum?sum/n:-1; } }; #include <string> ...