Как найти в файле числа строки c

HarryHarry

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Алгоритм решения: (предлагаю Вам переписать Ваш вариант)

1) Разбить строки на лексемы через stringstream

2) проверить цифры или нет

3) обработать (сделать то, что Вам нужно)

Вместо файла будет просто строка(представим что Вы туда сдампили файл) Вот Вам 2 схожих метода как это сделать

#include <iostream> 
#include <sstream> 
#include <algorithm>
#include <vector>
#include <cctype>
#include <iterator>


void foo(std::string str) {

    std::cout << "first" << std::endl;

    std::stringstream ss{ str };
    std::string tmp{};
    std::vector<int64_t> data_v;

    while (ss >> tmp) {
        if (std::all_of(std::begin(tmp), std::end(tmp), std::isdigit)) {
            data_v.push_back(std::stoi(tmp));
        }
    }

    for (const auto& v : data_v) {
        std::cout << v << std::endl;
    }
}


void foo2(std::string str) {

    std::cout << "second" << std::endl;


    std::stringstream ss(str);
    std::istream_iterator<std::string> begin(ss), end;
    std::vector<std::string> vec_str(begin, end);

    std::vector<int> data_v;

    auto f{ [&](const std::string& s) { if (std::count_if(std::begin(s), std::end(s), std::isdigit) == s.size()) { data_v.push_back(std::atoi(s.c_str())); }} };
    std::for_each(std::begin(vec_str), std::end(vec_str), f);

    for (const auto& v : data_v) {
        std::cout << v << std::endl;
    }
}


int main() {

    std::string str{ "num 10 num 20" };

    foo(str);

    foo2(str);

    return 0;
}

ответ дан 24 янв 2020 в 20:13

asked Jan 19, 2011 at 10:24

d+ is the regex for an integer number. So

//System.Text.RegularExpressions.Regex
resultString = Regex.Match(subjectString, @"d+").Value;

returns a string containing the first occurrence of a number in subjectString.

Int32.Parse(resultString) will then give you the number.

Here’s how I cleanse phone numbers to get the digits only:

string numericPhone = new String(phone.Where(Char.IsDigit).ToArray());

answered Mar 27, 2013 at 21:07

go through the string and use Char.IsDigit

string a = "str123";
string b = string.Empty;
int val;

for (int i=0; i< a.Length; i++)
{
    if (Char.IsDigit(a[i]))
        b += a[i];
}

if (b.Length>0)
    val = int.Parse(b);

use regular expression …

Regex re = new Regex(@"d+");
Match m = re.Match("test 66");

if (m.Success)
{
    Console.WriteLine(string.Format("RegEx found " + m.Value + " at position " + m.Index.ToString()));
}
else
{
    Console.WriteLine("You didn't enter a string containing a number!");
}

answered Jan 19, 2011 at 10:27

What I use to get Phone Numbers without any punctuation…

var phone = "(787) 763-6511";

string.Join("", phone.ToCharArray().Where(Char.IsDigit));

// result: 7877636511

answered Jan 16, 2015 at 14:55

Regex.Split can extract numbers from strings. You get all the numbers that are found in a string.

string input = "There are 4 numbers in this string: 40, 30, and 10.";
// Split on one or more non-digit characters.
string[] numbers = Regex.Split(input, @"D+");
foreach (string value in numbers)
{
    if (!string.IsNullOrEmpty(value))
    {
    int i = int.Parse(value);
    Console.WriteLine("Number: {0}", i);
    }
}

Output:

Number: 4
Number: 40
Number: 30
Number: 10

answered Oct 15, 2013 at 20:11

if the number has a decimal points, you can use below

using System;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            //Your code goes here
            Console.WriteLine(Regex.Match("anything 876.8 anything", @"d+.*d*").Value);
            Console.WriteLine(Regex.Match("anything 876 anything", @"d+.*d*").Value);
            Console.WriteLine(Regex.Match("$876435", @"d+.*d*").Value);
            Console.WriteLine(Regex.Match("$876.435", @"d+.*d*").Value);
        }
    }
}

results :

“anything 876.8 anything” ==> 876.8

“anything 876 anything” ==> 876

“$876435” ==> 876435

“$876.435” ==> 876.435

Sample : https://dotnetfiddle.net/IrtqVt

Here’s a Linq version:

string s = "123iuow45ss";
var getNumbers = (from t in s
                  where char.IsDigit(t)
                  select t).ToArray();
Console.WriteLine(new string(getNumbers));

Another simple solution using Regex
You should need to use this

using System.Text.RegularExpressions;

and the code is

string var = "Hello3453232wor705Ld";
string mystr = Regex.Replace(var, @"d", "");
string mynumber = Regex.Replace(var, @"D", "");
Console.WriteLine(mystr);
Console.WriteLine(mynumber);

answered Jan 18, 2014 at 11:03

You can also try this

string.Join(null,System.Text.RegularExpressions.Regex.Split(expr, "[^\d]"));

answered Jan 19, 2011 at 10:27

fubofubo

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Daniel GehrigerDaniel Gehriger

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 string input = "Hello 20, I am 30 and he is 40";
 var numbers = Regex.Matches(input, @"d+").OfType<Match>().Select(m => int.Parse(m.Value)).ToArray();

answered Aug 18, 2017 at 18:08

answered Dec 15, 2016 at 17:31

Richard FuRichard Fu

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spenderspender

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answered May 2, 2018 at 19:53

I have used this one-liner to pull all numbers from any string.

var phoneNumber = "(555)123-4567";
var numsOnly = string.Join("", new Regex("[0-9]").Matches(phoneNumber)); // 5551234567

answered Mar 20, 2021 at 2:30

  string verificationCode ="dmdsnjds5344gfgk65585";
            string code = "";
            Regex r1 = new Regex("\d+");
          Match m1 = r1.Match(verificationCode);
           while (m1.Success)
            {
                code += m1.Value;
                m1 = m1.NextMatch();
            }

answered Feb 27, 2013 at 5:56

Did the reverse of one of the answers to this question:
How to remove numbers from string using Regex.Replace?

// Pull out only the numbers from the string using LINQ

var numbersFromString = new String(input.Where(x => x >= '0' && x <= '9').ToArray());

var numericVal = Int32.Parse(numbersFromString);

static string GetdigitFromString(string str)
    {
        char[] refArray = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
        char[] inputArray = str.ToCharArray();
        string ext = string.Empty;
        foreach (char item in inputArray)
        {
            if (refArray.Contains(item))
            {
                ext += item.ToString();
            }
        }
        return ext;
    }

answered Jan 13, 2013 at 0:43

Sachin ShanbhagSachin Shanbhag

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user2320464user2320464

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Почитайте вот здесь – stackoverflow.com/questions/9673708/tell-cin-to-st…
А именно следующий код:

std::string line;
std::getline(cin, line);
std::istringstream iss(line);
while (iss >> c) {    
    vec.push_back(c);
}

Объект istringstream инициализируется строкой, и позволяет работать с ней как с потоком.

P.S. Не забудьте подключить sstream

Я не очень хорошо понял вашего вопроса.
Если файл дан в таком виде:

0 1 2 3 4
5 6 7 8 9
….

То можно использовать потоковый ввод.

ifstream file("fileName");
int number;
...
file >> number;

Но, возможно, я вас неправильно понял.