Thread: writing a pair of numbers to an array

Originally Posted by laserlight

Oh wait... I should have read instead of assumed. struct coordinates is a type name. The struct object of that type is named number1. As such, you should write:

Code:

read_location(&number1.x, &number1.y);

By the way, number1 should be a local variable instead.

Thanks for the clarification laserlight. As for the number1, do you mean I should move it into the read_location function?

Originally Posted by laserlight

No, into the main function.

im assuming you were referring to the "struct coordinates number1". in that case, i took your advice and moved it into main. Thanks

Also would

Code:

struct coordinates array[];

be the best way to store the values into an array? I was thinking about putting this in a loop that will keep adding new pairs to the array

Originally Posted by ssharish2005

Well no. Here is something which could help

1. Define a structure which hold your two integer values

Code:

struct node
{
    int num1;
    int num2;
};

2. Declare an array of that struct.

Code:

struct node array[20];

3. And then read value into it.

Code:

while( index < 20 )
{
    read_location( &array[index].num1, &array[index].num2 ) or
    read_location( &array[index] )
    index++;
}

Thats 3rd step would depend on how you defined your read_location function.

-ssharish

Thanks for the good advice, how can I test to see if the values stored are accurate before i continue with my code? I have this line following the loop to see if the 4th element is what i told it to be:

Code:

printf("%d", &array[3].x);

but this keeps displaying random numbers.

calls to the printf() function should not include the ampersand in them:

Remove the &.

Originally Posted by Adak

calls to the printf() function should not include the ampersand in them:

Remove the &.

I forgot to say, if I have it without the "&", it just displays a "1" every time, no matter what number i choose to enter.

Printf() calls, never include the ampersand - unless you want to print the address of the variable, in memory.

Your incorrect result is caused by other problems in your code. Why don't you print your latest full program, and i'll take a look at it?

I rewrote the program since I lost track of what I was doing the first time, heres what i have now:

Code:

#include <stdio.h>

struct coord{
	double x;
	double y;
};

struct coord array[20];

int main ()
{
	int index=0;
	do
	{
		read_location( &array[index].x, &array[index].y);
		index++;
	}while(index < 5);
	
	printf("%d", array[3].x);
	return 0;
}

int read_location(double *x, double *y)
{
	printf("Enter x:\n");
	scanf("%lf", &x);
	printf("Enter y:\n");
	scanf("%lf", &y);
}

Now im thinking the issue is in the "read_location" function. Thanks for the help, its much appreciated