How to separate a word with white spaces into two columns in C++

Question

I have a file contains a list of phone numbers in the following form:

Arvind 72580931
Sachin 7252890

My question is how can we display the contents in two columns?

Answer 1

First You need to parse each line in the list of phone numbers for get name and phone number. Then You need to format the output, You can use std::setw(int) to specify the width of the output. For example:

#include <iostream>
#include <string>
#include <iomanip>
#include <vector>

std::vector<std::string> stringTokenizer(const std::string& str, const std::string& delimiter) {
    size_t prev = 0, next = 0, len;
    std::vector<std::string> tokens;

    while ((next = str.find(delimiter, prev)) != std::string::npos) {
        len = next - prev;
        if (len > 0) {
            tokens.push_back(str.substr(prev, len));
        }
        prev = next + delimiter.size();
    }

    if (prev < str.size()) {
        tokens.push_back(str.substr(prev));
    }

    return tokens;
}

int main() {
    const int size_name = 20, size_phone = 10;
    std::cout << std::setw(size_name) << "NAME" << std::setw(size_phone) << "PHONE" << std::endl;

    std::vector<std::string> directory = {
        "Arvind 72580931",
        "Sachin 7252890",
        "Josh_Mary_Valencia 7252890"
    };

    for (const std::string& contact : directory) {
        std::vector<std::string> data = stringTokenizer(contact, " ");
        std::cout << std::setw(size_name) << data.at(0) << std::setw(size_phone) << data.at(1) << std::endl;
    }
}

Output:

                NAME     PHONE
              Arvind  72580931
              Sachin   7252890
  Josh_Mary_Valencia   7252890

Answer 2

If you want to display the output in the form of two columns you can maybe consider adding a tab character (or two) in between them.

cout << "name" << '\t' << "phone" << endl;