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How could I access a text file and go through word by word. I understand how to open the file but just not how to pull out each word one by one. I think it has something to do with arrays?
Simply:
#include <fstream>
#include <iostream>
int main()
{
std::fstream file("table1.txt");
std::string word;
while (file >> word)
{
// do whatever you want, e.g. print:
std::cout << word << std::endl;
}
file.close();
return 0;
}
word variable will contain every single word from a text file (words should be separated by space in your file).
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I have string str = "6.5.1"
I want to write str to file .txt, but the result is ��j
Here my code
FILE *outfile = fopen("solution.txt", "w");
string test = "6.5.1";
fprintf(outfile, "%s\n", test);
I use string, FILE because I want to pass FILE as an argument, and convert string from another file to method.
How can I fix this problem?
Thanks.
p\s: sorry, tag is c++ not c
You clarified that you needed a c++ solution and required to use FILE *:
#include <cstdio>
#include <string>
int main(void) {
FILE *outfile = std::fopen("solution.txt", "w");
std::string test = "6.5.1";
std::fprintf(outfile, "%s\n", test.c_str());
std::fclose(outfile);
}
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I'm sick and tired of solving why my ch[0] is of value "Thomas EdisonÇ#", when it should be "Thomas Edison"
int main(){
using namespace std;
ifstream in("U2.txt");
int n;
in>>n; //n=rows, so in every line there will be "name surname", time, money
char ch[n][21]; //I'm trying to get Name+Surname which must be 20 char long
in.read(ch[0], 20);
cout << ch[0]; //but getting Thomas EdisonÇ#
return 0;}
It works on one dimentional ch[21], but there's gonna be lots of values so I want to use ch[n][21]
Any other out of my box solution is welcome, I'm tired
You are forgetting that C strings need to be nul terminated
in.read(ch[0], 20);
ch[0][20] = '\0'; // add the nul terminator
cout << ch[0]; // now correct output
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I'm need to create id just number. For example: 12345678
If user inputs fail( contain char), delete char immediately.
For example: 123a =>input gain!
Please help me!
I think this is what you are looking for:
#include <iostream>
#include <string>
#include <cctype>
int main () {
std::string input;
bool valid;
do {
valid = true;
std::cin >> input;
for (char c : input)
if (! std::isdigit( static_cast<unsigned char>(c) ) )
valid = false;
} while (! valid);
// Here the string is guaranteed to be valid
}
Be aware though, that whatever you are trying to do, this does not look like the proper way to do it. There are ways to read numbers in c++, and this is not what I would recommend.
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So I'm a bit stumped on this, I'm reading a file with two types of lines that contain data, and they are started by a number followed by a comma. I need a way in order to match the lines with the same starting digit into a single line and output that. How would I even get started?
I'd do this by reading each line in two parts: the stuff before the comma, and the stuff after it.
Then I'd have a map (or unordered_map) with the value before the comma as the key, and the rest as the value associated with it.
std::map<std::string, std::string> data;
std::string key, value;
while (std::getline(infile, key, ',')) {
std::getline(infile, value);
data[key] += value;
}
Then (presumably) you'd want to write out the values:
for (auto const &v : data)
std::cout << v.first << ":" << v.second << "\n";
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I receive text with special characters (such as á) so I have to manually search and replace each one with code (in this case "á")
I would like to have code to search and replace such instances automatically after user input. Since I'm a noob, I'll show you the code I have so far - however meager it may be.
// Text fixer
#include <iostream>
#include <fstream>
#include <string>
int main(){
string input;
cout << "Input text";
cin >> input;
// this is where I'm at a loss. How should I manipulate the variable?
cout << input;
return 0;
}
Thank you!
An easy method is to use an array of substitution strings:
std::string replacement_text[???];
The idea is that you use the incoming character as the index into the array and extract the replacement text.
For example:
replacement_text[' '] = " ";
// ...
std::string new_string = replacement_text[input_character];
Another method is to use switch and case to convert the character.
Alternative techniques are a lookup table and std::map.
The lookup table could be an array of mapping structures:
struct Entry
{
char key;
std::string replacement_text;
}
Search the table using the key field to match the incoming character. Use the replacement_text to get the replacement text.