Text and Parsing Utilities

Parse Integer Text

std::stoi converts text containing digits into an integer value the program can calculate with.

stoi `std::stoi` parses a string and returns an `int`.
parsed value After parsing, the value behaves like any other integer.

Parse Integer Text

text
parse_integer_text.cpp
Replay: real traced execution (multi-file project)
#include <iostream>
#include <string>

int main() {
    std::string text = "42";

    int value = std::stoi(text);
    int doubled = value * 2;

    std::cout << "value=" << value << std::endl;
    std::cout << "doubled=" << doubled << std::endl;
    return 0;
}

#include <iostream>
#include <string>

int main() {
    std::string text = "7";

    int value = std::stoi(text);
    int doubled = value * 2;

    std::cout << "value=" << value << std::endl;
    std::cout << "doubled=" << doubled << std::endl;
    return 0;
}

#include <iostream>
#include <string>

int main() {
    std::string text = "105";

    int value = std::stoi(text);
    int doubled = value * 2;

    std::cout << "value=" << value << std::endl;
    std::cout << "doubled=" << doubled << std::endl;
    return 0;
}

  1. text ← 42, value ← 42, doubled ← 84

    4int main() {5    std::string text→ 42 = "42"; //@text="7", "105"67    int value→ 42 = std::stoi(text42);8    int doubled→ 84 = value42 * 2;910    std::cout << "value=" << value42 << std::endl;11    std::cout << "doubled=" << doubled84 << std::endl;12    return 0;13}
    outputvalue=42
doubled=84

  1. text ← 7, value ← 7, doubled ← 14

    4int main() {5    std::string text→ 7 = "7";67    int value→ 7 = std::stoi(text7);8    int doubled→ 14 = value7 * 2;910    std::cout << "value=" << value7 << std::endl;11    std::cout << "doubled=" << doubled14 << std::endl;12    return 0;13}
    outputvalue=7
doubled=14

  1. text ← 105, value ← 105, doubled ← 210

    4int main() {5    std::string text→ 105 = "105";67    int value→ 105 = std::stoi(text105);8    int doubled→ 210 = value105 * 2;910    std::cout << "value=" << value105 << std::endl;11    std::cout << "doubled=" << doubled210 << std::endl;12    return 0;13}
    outputvalue=105
doubled=210