Reading math equations in from file
I'm making a program where the users get a menu like this
Multiplication 1
Division 2
Subtraction 3
Addition 4
Review 5
where they can choose an option and put in the number range they want to work with and how many problems they want to do and it generates math problems for them.
That part works and I have it so when they get one wrong it puts the problem into a file math.txt using fout and that works.
What I'm trying to do now is when they choose to review it reads in the file and gives them those problems.
The file is in the format of (for example)
1 + 1 =
2 * 2 =
I'm just not sure how to read in the numbers and identify what operation it is (multiplication, addition etc.)
I've tried just getting it to read in a number with
std::ifstream fin("math.txt");
int x;
fin>>x;
But that returns 0 everytime.
So to summarize, my question is-- How can I read in a file and pull the equation (ex. 4 + 4 = n 3 / 3 = ) so that the user can solve it?
c++
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
add a comment |
I'm making a program where the users get a menu like this
Multiplication 1
Division 2
Subtraction 3
Addition 4
Review 5
where they can choose an option and put in the number range they want to work with and how many problems they want to do and it generates math problems for them.
That part works and I have it so when they get one wrong it puts the problem into a file math.txt using fout and that works.
What I'm trying to do now is when they choose to review it reads in the file and gives them those problems.
The file is in the format of (for example)
1 + 1 =
2 * 2 =
I'm just not sure how to read in the numbers and identify what operation it is (multiplication, addition etc.)
I've tried just getting it to read in a number with
std::ifstream fin("math.txt");
int x;
fin>>x;
But that returns 0 everytime.
So to summarize, my question is-- How can I read in a file and pull the equation (ex. 4 + 4 = n 3 / 3 = ) so that the user can solve it?
c++
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
2
Close voters: why Too Broad? OP is trying to read a single line from a file, what's broad about that?
– Tas
Nov 26 '18 at 22:24
Was the file opened correctly? You should check than before reading from it. (although I'm not sure if that's the problem here).
– Yksisarvinen
Nov 26 '18 at 22:32
add a comment |
I'm making a program where the users get a menu like this
Multiplication 1
Division 2
Subtraction 3
Addition 4
Review 5
where they can choose an option and put in the number range they want to work with and how many problems they want to do and it generates math problems for them.
That part works and I have it so when they get one wrong it puts the problem into a file math.txt using fout and that works.
What I'm trying to do now is when they choose to review it reads in the file and gives them those problems.
The file is in the format of (for example)
1 + 1 =
2 * 2 =
I'm just not sure how to read in the numbers and identify what operation it is (multiplication, addition etc.)
I've tried just getting it to read in a number with
std::ifstream fin("math.txt");
int x;
fin>>x;
But that returns 0 everytime.
So to summarize, my question is-- How can I read in a file and pull the equation (ex. 4 + 4 = n 3 / 3 = ) so that the user can solve it?
c++
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
I'm making a program where the users get a menu like this
Multiplication 1
Division 2
Subtraction 3
Addition 4
Review 5
where they can choose an option and put in the number range they want to work with and how many problems they want to do and it generates math problems for them.
That part works and I have it so when they get one wrong it puts the problem into a file math.txt using fout and that works.
What I'm trying to do now is when they choose to review it reads in the file and gives them those problems.
The file is in the format of (for example)
1 + 1 =
2 * 2 =
I'm just not sure how to read in the numbers and identify what operation it is (multiplication, addition etc.)
I've tried just getting it to read in a number with
std::ifstream fin("math.txt");
int x;
fin>>x;
But that returns 0 everytime.
So to summarize, my question is-- How can I read in a file and pull the equation (ex. 4 + 4 = n 3 / 3 = ) so that the user can solve it?
c++
c++
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
edited Nov 26 '18 at 22:21
Piotr Skotnicki
34.9k472118
34.9k472118
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
asked Nov 26 '18 at 22:19
Harmony KunzlerHarmony Kunzler
448
448
2
Close voters: why Too Broad? OP is trying to read a single line from a file, what's broad about that?
– Tas
Nov 26 '18 at 22:24
Was the file opened correctly? You should check than before reading from it. (although I'm not sure if that's the problem here).
– Yksisarvinen
Nov 26 '18 at 22:32
add a comment |
2
Close voters: why Too Broad? OP is trying to read a single line from a file, what's broad about that?
– Tas
Nov 26 '18 at 22:24
Was the file opened correctly? You should check than before reading from it. (although I'm not sure if that's the problem here).
– Yksisarvinen
Nov 26 '18 at 22:32
2
2
Close voters: why Too Broad? OP is trying to read a single line from a file, what's broad about that?
– Tas
Nov 26 '18 at 22:24
Close voters: why Too Broad? OP is trying to read a single line from a file, what's broad about that?
– Tas
Nov 26 '18 at 22:24
Was the file opened correctly? You should check than before reading from it. (although I'm not sure if that's the problem here).
– Yksisarvinen
Nov 26 '18 at 22:32
Was the file opened correctly? You should check than before reading from it. (although I'm not sure if that's the problem here).
– Yksisarvinen
Nov 26 '18 at 22:32
add a comment |
1 Answer
1
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oldest
votes
It sounds like the problem is that you haven't flushed the previous write operation. You can either do this explicitly with flush() or close() your fout instance. Example:
std::ofstream fou("math.txt");
fou << "1 + 1 =";
// Need this: fou.close();
std::ifstream fin("math.txt");
int x;
fin >> x;
std::cout << x;
I was able to reproduce your problem when fou.close() was missing.
answered Nov 26 '18 at 22:32
user10708715user10708715
461
add a comment |
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1 Answer
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1 Answer
1
active
oldest
votes
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oldest
votes
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oldest
votes
It sounds like the problem is that you haven't flushed the previous write operation. You can either do this explicitly with flush() or close() your fout instance. Example:
std::ofstream fou("math.txt");
fou << "1 + 1 =";
// Need this: fou.close();
std::ifstream fin("math.txt");
int x;
fin >> x;
std::cout << x;
I was able to reproduce your problem when fou.close() was missing.
answered Nov 26 '18 at 22:32
user10708715user10708715
461
add a comment |
It sounds like the problem is that you haven't flushed the previous write operation. You can either do this explicitly with flush() or close() your fout instance. Example:
std::ofstream fou("math.txt");
fou << "1 + 1 =";
// Need this: fou.close();
std::ifstream fin("math.txt");
int x;
fin >> x;
std::cout << x;
I was able to reproduce your problem when fou.close() was missing.
answered Nov 26 '18 at 22:32
user10708715user10708715
461
add a comment |
It sounds like the problem is that you haven't flushed the previous write operation. You can either do this explicitly with flush() or close() your fout instance. Example:
std::ofstream fou("math.txt");
fou << "1 + 1 =";
// Need this: fou.close();
std::ifstream fin("math.txt");
int x;
fin >> x;
std::cout << x;
I was able to reproduce your problem when fou.close() was missing.
answered Nov 26 '18 at 22:32
user10708715user10708715
461
It sounds like the problem is that you haven't flushed the previous write operation. You can either do this explicitly with flush() or close() your fout instance. Example:
std::ofstream fou("math.txt");
fou << "1 + 1 =";
// Need this: fou.close();
std::ifstream fin("math.txt");
int x;
fin >> x;
std::cout << x;
I was able to reproduce your problem when fou.close() was missing.
answered Nov 26 '18 at 22:32
user10708715user10708715
461
answered Nov 26 '18 at 22:32
user10708715user10708715
461
answered Nov 26 '18 at 22:32
user10708715user10708715
461
answered Nov 26 '18 at 22:32
user10708715user10708715
461
461
add a comment |
add a comment |
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2
Close voters: why Too Broad? OP is trying to read a single line from a file, what's broad about that?
– Tas
Nov 26 '18 at 22:24
Was the file opened correctly? You should check than before reading from it. (although I'm not sure if that's the problem here).
– Yksisarvinen
Nov 26 '18 at 22:32