ash22 - 6 months ago 20

C Question

`#include <stdio.h>`

#include <conio.h>

void main() {

int a, n, x;

clrscr();

printf("enter a number");

scanf("%d", &a);

n > 1;

a != n && n < a;

if (a / n == x)

printf("a is not a prime no");

else

printf("a is a prime no");

}

If I run this and put a composite number, it still shows it as prime.

Answer

your `if`

statement is never true duo to `n`

and `x`

are not initialized. Therefore you only get your else as return. Moreover your expression `n>1;`

and `a != n && n < a;`

return a bool which is not compered to anything. In that case you need to use a `for`

loop.

Here is a link About for loops

```
int main()
{
int a,n,x = 0;
printf("enter a number: ");
scanf("%d",&a);
for(n=2; n<=a/2; ++n)
{
if(a%n==0)
{
x=1;
break;
}
}
if (x==0)
printf("",n);
else
printf("a is not a prime no");
return 0;
}
```