I'm writing a program that converts hex to letters and writes the letters to a file.To write I'm currently using ofstream("output.txt" ios::app)But the issue with this is, is that everytime I run the program, it appends and doesn't write from the beginning of the text file.So what I want to know is, how do I clear the contents of a text file, before writing to it?
View 1 RepliesI was asked by my teacher to create while loop for this, iv have completely for gotten how and all the tutorial that i have found show basic lopping.
#include <iostream>
#include <iomanip>
using namespace std;
void checkAnswers(char[], char[], int, int);
int main(int argc, const char * argv[]) {
int choice = 0;
const int num_question=20;
const int min_correct=15;
char answers[num_question] ={
[Code] ....
I am currently having problems creating a loop that will allow my user to choose to return to the beginning of the program or quit.
#include <iostream>
using namespace std;
int main() {
int j;
do {float a;
cout << "+----Welcome to Basic Operations----+
| Select Your Operation |
[Code] .....
I have not yet finished designing the interface for a couple of the operations, but right now i am hung up on trying to return to the beginning. I believe it is because the j was defined inside do and isn't carried out of the do statement for while.
For my C programming module, I've been asked to create a program which is basically a ten question mathematics quiz or test if you like. Below is a copy and paste of my current, working program.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main () {
[Code]....
I am also trying to include into my program; If the user achieves 4 or less marks in the test, they are asked if they would like to repeat the test (have a second chance).
I have been asked by my Lecturer to ask the Question; "Would you like to try again" and the response is 'Y' for yes, 'N' for no. Would this be shown by:
char Y = Y;
char N = N;
printf("Would you like another go?");
scanf(%d%, &Y, &N);
And finally; If the user would like another go, then I am trying to include the code that clears the screen and then reloads the program?
What code is used to clear the screen and no clue what code is written to refresh or reload the program. I assume it's a loop statement or some sort.
When creating an exception mask for a file, should an exception throw during a file operation, I can reset the state bits of the actual file using ios::clear().
Though after doing so, will the exception mask still throw an exception, thinking that the specified error state flags are still set to true? If so, how can I reset the exception mask so that it is ready to throw more exceptions should the appropriate situations arise in the future?
Assuming that we have the string :
Code:
***HELLO&SIR. & and * is the delimiters.
My question is how strtok will work in the beginning?
According to this to determine the beginning and the end of a token, the function first scans from the starting location for the first character not contained in delimiters (which becomes the beginning of the token). And then scans starting from this beginning of the token for the first character contained in delimiters, which becomes the end of the token. The scan also stops if the terminating null character is found.
This end of the token is automatically replaced by a null-character, and the beginning of the token is returned by the function. strtok will replace the first * with '' and the next call will start from the second * puts '' there and again the same with the third * ?
I am writing another program and I cannot find for the life of me how to loop the program back to the start of a function.
Code:
#include <stdio.h>
#include <stdlib.h>
int main(void) {
int choice;
char band1, band2, band3, band4;
printf ("This program calculates the resistor value based on the colours of the wire.
(enter the integer near the command)
");
printf ("What would you like to do?
[Code].....
This is my current iteration of the program. Obviously, I haven't finished writing the case 1 of the first switch, but for the other ones. I thought that return main would cause the program to loop back to the beginning after executing the case, but I see that it is not the case (pun not intended). Anyways, what would I have to insert to cause the program to loop again (other than for case 3)? And another question, why is it that in scanf in the first case, the program only accepts two characters before finishing?
I've been struggling with linked list for a few days. I've tried performing a few operations. Here is my code. the add_begin() function doesn't seem to work.
#include<iostream>
using namespace std;
struct node {
int data;
node *next;
[Code] .....
I'm trying to learn structure type in C. In this trying, the code must take 9 value from user but it takes 6 values then returned. I scrutinized but I can't find my error.
#include <stdio.h>
typedef struct books {
char name;
float price;
int pages;
} book;
[code].....
How do you add a value to the beginning of a string instead of the end?
This is for an assignment and I have to convert the user input (always assuming its a valid decimal number) to binary and store it in a string. I've got up to dividing by two to get the remainder ...
My program had a requirement to ignore an input beginning with a # sign. The input is entered by user from keyboard. I wanted to know how to use cin.ignore to achieve this.
#include <iostream>
#include <algorithm>
#include <string>
#include <iomanip>
#include <limits>
#include <stdio.h>
using namespace std;
[Code] ....
The output:
Enter the string
# Comment
This is the # comment string.
Answer:
This is the string.
So I'm making my first program w/ C++ and its a game guessing game. I've learned how to use booleans, chars, strings, if/else, loops, and input. Anything past that I dont know. I've gotten my game to work properly except for the fact that when you guess incorrectly, the program closes. I want the program to go to the beginning of the program again so the user can restart. So far i've gotten the loop to beginning thing to work but not well. It'll only repeat twice before closing again and it'll say the user got the wrong answer even if it was correct. Here's my code
#include <iostream>
#include <string>
#include <random>
#include<ctime>
using namespace std;
int game(){
string playerName;
int guess;
[Code] ....
here is a nested stl map
typedef struct struct_RISCP {
float nSCPTotal;
int nSCPCount;
CString strIMEI;
std::map<UINT8, int> mapSection;
}RISCPSt;
map<stRncCellIdntyDmnType, RISCPSt>m_mapRISCP;
it occupied too much memory,i wanted to clear them(both outer map and inner map) ,some one told me you just need to call m_mapRISCP.clear(),then the mapSection (inner map) will be cleared automaticly,in other words, m_mapRISCP.clear() will clear both outer map and inner map.
How do I write a ROM BIOS routine which accepts a row number from the user and place the cursor to the beginning of the row number which the user gave?
View 2 Replies View RelatedI have a one simple question :D. I want to output to the console some symbols. Let's say that i have a loop.
for(int i = 0; i < 10; i++) cou << "* ";
Then I want to output other symbols but I want to overwrite the previous symbols. I know I can use system("cls"); but it blinks if I try to output the same characters. For example if I have:
for(int i = 0; i < 10; i++) cou << "* ";
system("cls");
for(int i = 0; i < 10; i++) cou << "* ";
After I run this code the first loop outputs ten "*". Then there is a blink and there are again ten "*" shown. How can I avoid this blink?
vector<int> *vec; allocate memory and
suppose vec conatins 10 values then
erase(vec->begin(),vec->end());
vec.clear();
both should be used or any one one is fine to erase all ??
Is there any way I can clear only a selected part of the screen? (I'm aware of system("cls"))
For example, when you enter a date, and is wrong, could it just errase that input and only say "Wrong try again" without errasing everything else you where doing?
In this case, a function that only errases what is in the while
while(not wrong)
{
cout<<"DIA: ";
cin>>obj.dia;
cout<<"MES: ";
cin>>obj.mes;
cout<<"ANIO: ";
cin>>obj.anio;
}
PS: Also, is there any whay in which you can ask the user to enter the date DD/MM/YYY?
I am trying to clear the first character of my array. The first two methods don't seem to work. The third method seems to but doesn't look like a good idea.
char operand[] = "abc";
//both methods seem to null it out
operand[0] = 0;
memset(operand, 0, 1);
printf("%s", operand);
//seems to work
memset(operand, 5, 1);
I need to clear a listbox from a class other than the form where it exists. Why this isn't working? I'm getting no error messages when I compile and I am seeing the Console.WriteLine text I also added in the same function. I can call this function from within my form and it behaves as expected. I tried setting the listbox to public despite the fact I wasn't getting protection level errors but that made no difference.
Just to clarify what I'm doing here... I have a form that includes a panel of user controls from another class. So there is a listbox on OtherClass and the listbox is in MyForm. Heres my code:
MyForm
public void ClearListBox() {
Console.WriteLine("echo");
listBox.Items.Clear();
} OtherClass
private void listBox_SelectedIndexChanged(object sender, EventArgs e) {
MyForm mf = new MyForm();
mf.ClearListBox();
}
How to clear data from a char array?
View 19 Replies View RelatedCode:
std::ostringstream ss;
ss.flush();
ss.clear();
ss << v.x;
std::string buff(ss.str());
XMLString::transcode(buff.c_str(), tempStr, 99);
[Code] ....
The buff at "Z" are stringed together with previous values. How do I resolve that?
I have a college project which is a car racing game using C++ and the old-school graphics library BGI. After I draw the map and placed the objects(Car,obstacles,road's borders etc..)I added Sleep(); function to the function named Obstacles(); but the problem is, I can't move the car with the right&left arrows.a
Another problem,If I added a cleardevice(); command all objects disappears only the obstacles function keeps working. the Code is here:
char c;
do{
c = (char)getch();
if (c == KEY_LEFT) {
x = x - 10, x1 = x1 - 10;
} if (c == KEY_RIGHT) {
x = x + 10, x1 = x1 + 10;
[code].....
note: this is not the whole code, it's only a small portion of it, not a debugging question only need a hint how to fix it.
I checked through the net and most of the solution like clrcr(); is not working for microsoft visual 2010. SO i was wondering for those who was using the same ver of c++ as me how do you clear the screen?
View 5 Replies View RelatedI have 2 datagridview in one windows form, When I click row from datagridview1, it shows in datagridview2 (Select *from....). Also I have combobox column in datagridview2. My question is, when I select items in combobox, and click to new row in datagridview 1, datagridview2 combobox's is getting empty. it is my code:
private void dataGridView1_CellDoubleClick_1(object sender, DataGridViewCellEventArgs e) {
try {
int id = Convert.ToInt32
(dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells["id"].Value);//3
[Code] .....
I've got myself a 2d array
int[,] map = new int[100,100];
I've populate that will a bunch of 1's and 0's. The 1 represents a wall, and a 0 is dirt.
I'm looking for a way to clean up my blank spaces outside of my walls. Any algorithm I can use to identify these big areas and replace them with a '1'
for (int y = 1; y < map.GetLength(1) - 1; y++) {
for (int x = 1; x < map.GetLength(0) - 1; x++) {
// Inside here is where I was hoping to archive my work
bool draw = true;
foreach (Room room in rooms)
[Code] ....
Attached is an example of my output.As you will be able to see, there is a lot of brown. I want to fill the brown with walls, but leave space for a path between the rooms.The 'draw' bool is true when I'm outside of a room, just so I don't start throwing walls inside my room.
Example of what the array would look like (for those who don't know)
int[,] map = new int[100,100]
{
{0,1,1,1,1,1,0},
{0,1,0,0,0,1,0},
{0,1,0,0,0,1,0},
{0,1,0,0,0,1,0},
{0,1,0,0,0,1,0},
{0,1,1,1,1,1,0},
};
How I can clear the whole screen in console...
And I'm using clrscr(); and its not working.
How i can change the text color in the .exe without using system function