Thread: Need help in a fairly simple C prog

Having a little trouble with a basic program that i wrote. it's supposed to convert the digital number input into a text output. when i compile the program it shows no errors but when i run it it has an error that causes it to close. I'm trying to teach myself c prog right now but there's always questions that arise. Thanks

Code:

#include <stdio.h>

int main()
{
int num1;
float num1;

printf("Please enter a single digit number:");
scanf("%f",num1);

if(num1==1)
printf("%s %f","You entered the number one",num1);

else if(num1==2)
printf("%s %f","You entered the number two",num1);

else if(num1==3)
printf("%s %f","You entered the number three",num1);

else if(num1==4)
printf("%s %f","You entered the number four",num1);

else if(num1==5)
printf("%s %f","You entered the number five",num1);

else if(num1==6)
printf("%s %f","You entered the number six",num1);

else if(num1==7)
printf("%s %f","You entered the number seven",num1);

else if(num1==8)
printf("%s %f","You entered the number eight",num1);

else if(num1==9)
printf("%s %f","You entered the number nine",num1);

else
printf("error");

scanf("%f", num1");
return 0;

}

Code:

int num1;
float num1;

you cant declare the same variable for two data types....
remove one of them...

Code:

printf("%s %f","You entered the number one",num1);

the syntax of your printf is wrong....

when u want to print a constant string like "hello" you don't need a %s


so your correct statement would be...

Code:

printf("you entered the number one %f",num1);

the output would be...

you entered the number one 1

try using a switch case instead of elseif ladder....

why are you using scanf before return 0.... kindly explain...
you can as well remove that

I fixed all the things you mentioned. I noticed that i declared num1 twice after i posted.
I ran the program and still got the error that causes the program to crash.

I've had problems with having my programs stay open after they perform their function. I was told before that if i throw a random scanf at the bottom then the program would be looking for a value and pretty much hold until if found that value.

The reason i chose to use the elseif ladder is because the book that im reading through gives only 2 examples of switch so im not so clear on that. i'll give it a shot

Code:

printf("Please enter a single digit number:");
scanf("%f",&num1);

That's one error that popped right up, You must save the scanf to the adress, not the variable itself.

Also, you're much better off using Switch, Let me jsut write a small example.

Code:

int main(void){
int op;

printf("Insert a Number > ");
scanf("%d",&op);

switch(op)
{
   case 1: printf("The Number you've inserted is one"); break;
   case 2: printf("The number you've inserted is two"); break;
    . . . 
   case 9: printf("The Number you've inserted is nine"); break;
   default: printf("Wrong Number introdution");
}
return 0;
}

"Case" lets you put all the expected cases you have, in this case, I should be form 0 to 9. And default, is if the program reads anythign different form that cases, so, if you type 10, it will not detect an option, and returns that error message!

One other thing, I think the scanf call is wrong. Need a & in there(pointers - there fun and scary and your probably still work your way up to them).

Heres a version with a switch in it. Pretty simple.

If your on windows, you can add system("PAUSE") to the end of you program instead of the scanf. Or you could just start it from a console/shell(aka cmd).

Code:

#include <stdio.h>

int main() {
	int num1;
	
	printf("Please enter a single digit number:");
	scanf("%i", &num1);
	
	switch(num1) {
		case 1:
			printf("You entered the number one %i", num1);
			break;
		case 2:
			printf("You entered the number two %i", num1);
			break;
		case 3:
			printf("You entered the number three %i", num1);
			break;
		case 4:
			printf("You entered the number four %i", num1);
			break;
		case 5:
			printf("You entered the number five %i", num1);
			break;
		case 6:
			printf("You entered the number size %i", num1);
			break;
		case 7:
			printf("You entered the number seven %i", num1);
			break;
		case 8:
			printf("You entered the number eight %i", num1);
			break;
		case 9:
			printf("You entered the number nine %i", num1);
			break;
		default:
			printf("error");
	}
	
	return 0;
}