How can I convert a std string to int

0 votes
I don't mean ASCII codes when I say I want to convert a string to an int.

For a brief recap, we're given an equation in the form of a string.

We must deconstruct it, accurately format it, and solve the linear equations.

To be clear, I am unable to convert a string to an int.

I know the string will be in the format (-5) or (25) or something similar, so it's definitely an int.

But how do we get that information out of a string?

Running a for/while loop through the text, checking for a digit, extracting all the digits after that, and then looking for a leading '-', if there is, multiplying the int by -1.
May 31 in C++ by Nicholas
• 5,020 points
41 views

1 answer to this question.

0 votes

There are some new convert methods in C++ that convert std::string to a numeric type.

As an alternative to

str.c str() atoi(str.c str()) atoi(str.c str()

you can make use of

std::stoi std::stoi std::s ( str )

where str is your std::string number.

There are versions for all types of integers, including 

long stol(string), float stof(string), and double stod(string) (string)
answered Jun 1 by Damon
• 4,960 points

Related Questions In C++

0 votes
0 answers

How to convert a char array to a string?

Converting a C++ string to a char ...READ MORE

Jul 14 in C++ by Nicholas
• 5,020 points
23 views
0 votes
0 answers

How to initialize an std::string with a length?

How can I correctly initialise a string if its length is specified at build time? #include <string> int length = 3; string word[length]; //invalid ...READ MORE

Jul 27 in C++ by Nicholas
• 5,020 points
9 views
0 votes
0 answers

How can I get double quotes into a string literal?

I used the printf() command to produce the output seen below: printf("She said time flies like an arrow, ...READ MORE

Aug 5 in C++ by Nicholas
• 5,020 points
12 views
0 votes
1 answer

Easiest way to convert int to string in C++

std::stoi (and variations for each numeric type) ...READ MORE

answered Jun 15 in C++ by Damon
• 4,960 points
55 views
0 votes
1 answer

Easiest way to convert int to string in C++

The C++11 version has introduced the std::stoi ...READ MORE

answered Feb 10 in Others by Rahul
• 9,000 points
39 views
0 votes
1 answer

Converting integer to string in Python

In order to convert an object to string ...READ MORE

answered Feb 11 in Python by Dev
• 6,000 points
31 views
0 votes
0 answers

How to convert a string to an integer in JavaScript?

How do I convert a string to ...READ MORE

May 2 in Others by Kichu
• 19,040 points
56 views
0 votes
1 answer

How to reverse an std::string?

A reverse function is integrated into C++ and can be used to reverse a string.  This function accepts two parameters: The start iterator for the string The string iterator has come to an end. The following line of code demonstrates how to use this function: #include <iostream> //The library below must be included ...READ MORE

answered Jun 1 in C++ by Damon
• 4,960 points
33 views
0 votes
1 answer

How to convert an instance of std::string to lower case

#include <algorithm> #include <cctype> #include <string> std::string data = "Abc"; std::transform(data.begin(), ...READ MORE

answered Aug 2 in C++ by Damon
• 4,960 points
8 views
0 votes
1 answer

Easiest way to convert int to string in C++

C++ adds std::stoi (and variants for each numeric type) and std::to string, which are the C equivalents of atoi and itoa but expressed in terms of std::string #include <string> std::string s = std::to_string(42); Is therefore ...READ MORE

answered Jun 1 in C++ by Damon
• 4,960 points
53 views
webinar REGISTER FOR FREE WEBINAR X
Send OTP
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP