CODEWITHSUNDEEP
c++arraysiostream
Rawley Fowler
Rawley Fowler

Reputation: 2544

How to input multiple values from a txt file into an array C++

I am looking to input individual inputs of a .txt file into my array where each input is separated by a space. Then cout these inputs. How do I input multiple values from the .txt file into my array?

    int main()
{
    float tempTable[10];

    ifstream input;
    input.open("temperature.txt");

    for (int i = 0; i < 10; i++)
    {
        input >> tempTable[i];
        cout << tempTable[i];
    }

    input.close();

    return 0;
}

With what I have written here I would expect an input of the file to go according to plan with each value entering tempTable[i] however when run the program out puts extreme numbers, i.e -1.3e9.

The temperature.txt file is as follows:

25 20 11.2 30 12.5 3.5 10 13

Upvotes: 0

Views: 941

Answers (2)

SHR
SHR

Reputation: 8313

Your file contains 8 elements, you iterate 10 times.

You should use vector or list and iterate while(succeded)

#include <vector>
#include <fstream>
#include <iostream>
int main()
{
    float temp;    
    std::ifstream input;
    input.open("temperature.txt");
    std::vector<float> tempTable;
    while (input >> temp)
    {
        tempTable.push_back(temp);
        //print last element of vector: (with a space!)
        std::cout << *tempTable.rbegin()<< " ";
    }
    input.close();
    return 0;
}

Upvotes: 1

camp0
camp0

Reputation: 392

You can use boost::split or directly assing the descriptor to variables

std::ifstream infile("file.txt");

while (infile >> value1 >> value2 >> value3) {
    // process value1, value2, ....
}

Or use the other version

std::vector<std::string> items;
std::string line;

while (std::getline(infile, line)) {
    boost::split(items, line, boost::is_any_of(" "));
    // process the items
}

Upvotes: 0

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