string problem

[spikerotc04]

I'm still trying to figure out how to loop through a string so that every time I loop through it the list will be updated with the most recent values at the top.

This is what I have, but it is not working:

//Declarations
char startunit[20][5];
	char endunit[20][5];
	char filename[20][15];

//string assignments
	strcpy(startunit[i],"mm");
	strcpy(endunit[i],"mm");
	strcpy(filename[i],"mm.txt");

//display
       printf("%s", startunit[i]);
	printf("%s", endunit[i]);
	printf("%s", filename[i]);

All I get is some garbage that displays.

I only have 10.5 hrs till this is due. I really need some help on this. Once I figure this problem out it will be easy for me to complete my project.

Thanks.

[swoopy]

I see nothing wrong with anything you've posted. Some things to check would be:
(1) Make sure i runs from 0 to 19 (using a for-loop for (i=0; i<20; i++))
(2) Make sure startunit and endunit are no more than 4 characters.

[spikerotc04]

I could not get it to work.
I am going to post my entire code so I might be able to get some help with this. I t keeps displaying garbage. I only have part of it posted, and the declarations are only used in one case if the switch statement so I can test it. Sorry about the length.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>


int main(int argc, char *argv[])
{
	char check[5];
	int i=0;
	int j=1;
	int start;
    int start1;
    int end;
	double mm;
	double ans;
	FILE *mmptr;
	char startunit[20][5];
	char endunit[20][5];
	char filename[20][15];
	
    printf("Welcome to Casey's Conversion Program\n");
    
    
    startunit[i] == startunit[i+1];
    endunit[i] == endunit[i+1];
    filename[i] == filename[i+1];
	
    /* loop to rerun program */
	
    do{
            
	printf("Enter:\n1 for Length Conversion\n");
	printf("2 for Area Conversion\n");
	printf("3 for Volume Conversion\n");
	printf("4 for Time Conversion\n");
	printf("5 for Angle Conversion\n");
	printf("6 for Speed Conversion\n");
	printf("7 for Acceleration Conversion\n");
	printf("8 for Mass Conversion\n");
	printf("9 for Force Conversion\n");
	printf("10 for Pressure Conversion\n");
	printf("11 for Energy Conversion\n");
	printf("12 for Power Conversion\n");
	scanf("%d", &start);

/*Length Conversion*/

	switch(start){
		
        case 1:
    
    printf("Enter starting unit: \n");
	printf("1 for millimeters\n");
	printf("2 for centimeters\n");
	printf("3 for meters\n");
	printf("4 for kilometers\n");
	printf("5 for inches\n");
	printf("6 for feet\n");
	printf("7 for yards\n");
	printf("8 for miles\n");
	scanf("%d", &start1);

	switch(start1){
 
         case 1:
			
   mmptr = fopen("mm.txt", "a");
	
	printf("Enter the number of millimeters: ");
	scanf("%lf", &mm);
	
	printf("Enter ending unit: \n");
	printf("1 for millimeters\n");
	printf("2 for centimeters\n");
	printf("3 for meters\n");
	printf("4 for kilometers\n");
	printf("5 for inches\n");
	printf("6 for feet\n");
	printf("7 for yards\n");
	printf("8 for miles\n");
	scanf("%d", &end);
	
	/*Converts from mm*/
	
	switch(end){      

		case 1:
			ans = mm;
			printf("%lf millimeters equals %lf millimeters\n", mm, ans);
			fprintf(mmptr,"%lf mm = %lf mm\n", mm, ans);
			strcpy(startunit[i],"mm");
			strcpy(endunit[i],"mm");
			strcpy(filename[i],"mm.txt");
        
			break;
     
		default:
			printf("Not valid entry\n");
			break;
        
	i++;
    fclose(mmptr);
    }
          }
                }

		printf("Do you want to continue (y for yes)? ");
		scanf("%s", check);
		
	}while(strcmp("y", check) == 0);
	
	
	printf("Starting Unit\t\tEnding Unit\t\tFilename\n");

for(i=0;i<20;i++){
        printf("%s", startunit[i]);
	printf("%s", endunit[i]);
	printf("%s", filename[i]);
	             }
	
    system("PAUSE");	
	return 0;
}

[swoopy]

> i++;
Notice this statement is within your default case, so the only time i gets incremented is when "Not valid entry" is printed.

Some other things:
> startunit[i] == startunit[i+1];
> endunit[i] == endunit[i+1];
> filename[i] == filename[i+1];
These statements basically don't do anything, as == is for equality. I'm not sure for what purpose you intended them.

>for(i=0;i<20;i++){
> printf("%s", startunit[i]);
> printf("%s", endunit[i]);
> printf("%s", filename[i]);

Unless you actually have twenty entries, the unused entries probably will print garbage. Since you're incrementing i as you enter data, here you could say:
for (j=0; j<i; j++)
Of course, you probably also want to be sure during the first while-loop that i doesn't get incremented if "Not valid entry" is printed.

[swoopy]

> fprintf(mmptr,"%lf mm = %lf mm\n", mm, ans);
%lf is really for scanning doubles. For printing doubles use %f. Some compilers will take %lf, but %f is more portable.