how to convert a string into an int c++ code example

Example 1: convert stirng to int c++

int thing = std::stoi(string);

Example 2: string to int c++

#include <iostream>
#include <string>

int main() {

    std::string str = "123";
    int num;

    // using stoi() to store the value of str1 to x
    num = std::stoi(str);

    std::cout << num;

    return 0;
}

Example 3: string to number in c++

// For C++11 and later versions
string str1 = "45"; 
string str2 = "3.14159"; 
string str3 = "31337 geek"; 

int myint1 = stoi(str1); 
int myint2 = stoi(str2); 
int myint3 = stoi(str3); 

// Output
stoi("45") is 45
stoi("3.14159") is 3
stoi("31337 geek") is 31337

Example 4: convert string to number c++

//stoi() : The stoi() function takes a string as an argument and 
//returns its value. Supports C++11 or above. 
// If number > 10^9 , use stoll().
#include <iostream>
#include <string>
using namespace std;
main() {
	string str = "12345678";
	cout << stoi(str);
}

Example 5: c++ string to int

// EXAMPLE
std::string sStringAsString = "789";
int iStringAsInt = atoi( sStringAsString.c_str() );

/* SYNTAX
atoi( <your-string>.c_str() )
*/

/* HEADERS
#include <cstring>
#include <string>
*/