Thread: Data held concurrently in the memory.

this is the requirement
Up to 100 pit data entries can be held
concurrently in the laptop memory.
Entering new pit data:
1- The user selects 'd' or 'D' from the menu.
2- The user enters the pit location name.
3- The program prompts for entry of the time
for a stone to hit the pit bottom (measured
using a stopwatch). Several measures can be
taken in succession.
4- Only the last depth estimate is recorded to
memory as the user enter 'n' or 'N' when asked
whether to take another measure.


HOW DOES THE DATA GET STORED IN MEMORY?

You put it there, presumably, by writing it to mydata[63] or some such. What exactly is your question about?

when the user enter 'no', only the last septh estimate should get recorded in the memory.
how can i do that?
insert

Code:

#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <stdlib.h>
bool yesNo(const char prompt[]);
double depth(double seconds2Bottom);
double toBottom;
char location[80], filename[80];
int i;
FILE *fileptr;
int main(void)
{
   char choice='j';
   while (choice !=('q'||'Q'))
   {
        printf("\t\t\tMain Menu\n\n");
        printf("(D)epth: Enter pit location, Compute depth	  \n");
        printf("(S)ave : Write pits data to file 	\n");
        printf("(L)oad : Read mine shaft information from file.\n");
        printf("(P)rint: Display mine shaft information.\n");
        printf("(Q)uit : Exit program.\n");
	    printf("Enter choice(D/S/L/P/Q)\n\n");
        scanf("&#37;c",&choice);
        fflush(stdin);
        switch (choice)
		{
		
			case 'q': case 'Q':
			   
			    printf("GOOD BYE\n\n\n");
				return 'j';
				break;
				
			case 'd': case 'D':
			   
		    	do
				{
				   printf("\n Enter mine shaft location or name:\n");
	               fgets(location, 80, stdin);
		       	   printf(("%s", location);
				   printf("\nEnter time in seconds to bottom: \n");
	               scanf("%i ", &toBottom);
				   fflush(stdin);
	               printf("\nShaft depth is %.2f m\n", depth(toBottom));
				}  while( yesNo("Do you want to take another measure"));
				
				break;
		
			case 's': case 'S':
		        
			   printf("\n Enter name of file to enter pit data to:\n");
               gets (filename);
		       if((fileptr=fopen(filename, "a"))==NULL)
		       {
		       printf("Error: cannot open input file for writing\n");
			   exit(0);
		       }	
			   else   
          
				break;
				
			case 'l': case 'L':
			
				printf("Modify selected\n");
				break;
				
			case 'p': case 'P':
				printf("Backup selected\n");
				break;
			default:
				printf("Invalid selection. Please try again.\n");
		} /*end of switch*/
	} /*end of while*/
   
  
 
 /* Pause, then exit */
    printf("Press [Enter] to exit. ");
    getchar();
    return 0;
}

bool yesNo(const char prompt[])
{
	char answer;
	printf("\n%s (Y/N)? ", prompt);
	answer = getchar();
	fflush(stdin);
	return (answer == 'y' || answer == 'Y');
}



double depth(double seconds2Bottom)
{
	/* Acceleration of gravity */
	const double G = 9.81;
	
	return -0.5 * G * seconds2Bottom * seconds2Bottom; 
}

I would request a piece of memory (using, say, malloc) big enough to hold both location and depth, and then write the location and depth to that piece of memory.

It might be easier to collect your data in a struct that keeps the location and depth together in one object.

If you know ahead of time some limit on the number of pits you will have, then you can declare an array of those structs, thus getting a bunch of memory all in one shot, meaning writing to the memory would just mean writing to list_of_pits[14] or whatever.

user enter 'n' or 'N' when asked
whether to take another measure

last depth calculated should get stored in memory.
got struck here.location data will get stored in location string, i know that i need to use parallel arrays but how?
insert

Code:

		  do
    	 {   
	        printf("\n Enter mine shaft location or name:\n");
	        fgets(location, 80, stdin);
			printf(("%s", location);
	    	printf("\nEnter time in seconds to bottom:\n ");
	    	fflush(stdin);
	    	printf("\nShaft depth is %.2f m\n", depth(toBottom));
  	      } while( yesNo("Do you want to take another measure"));