You'll have to cast the int into a double.

 

Quote:

Originally Posted by corrinthians

You'll have to cast the int into a double.

This. To do the cast just type:

Code:

purchasePrice = (double)a + b;

 

It's nice to add an explanation.

Why cast? Because you're adding a integer to a double and the compiler will automatically cast the double to integer, losing all decimal cases, and returning an integer to the purchaseValue. When specifically casting the integer to a double, (double) a, you're saying to the compiler to treat a as a double instead of an integer, in that specific operation.

 

thnx u guys. but it still doesnt work

 

If you try printing b directly after your scanf call, you will see that b is actually zero no matter what value you enter. This is because you are telling scanf to interpret the input as a float, but you are trying to store it in a double.

You must use %lf in your scanf to read the input as a double. Alternatively, you can store your numbers as floats instead of doubles (the precision difference won't matter for your code).

To everyone suggesting a cast. The integer will be automatically promoted to a float in the addition, so the cast has no effect.

ps. Please use code tags in future

 

Code:

int main(void) {
        int a;
        double b;

        printf("\nNumber of items purchased\n");
        scanf("%d", &a);;

        printf("\nEnter the Unit Price\n");
        scanf("%lf", &b);

        printf("\nPurchase Price is %.2lf", a + b);
}

That should work for you, the problem was you need to use %lf for doubles (long float), %f is for float.

 

thanx all u guys!!

 

this works yay!

 

Quote:

Originally Posted by RAND0M1ZER

That should work for you, the problem was you need to use %lf for doubles (long float), %f is for float.

Noticed that too but what I didn't understand is why "%.2lf" and not just "%lf".

 

Quote:

Originally Posted by adridu59

Quote:

Originally Posted by RAND0M1ZER

That should work for you, the problem was you need to use %lf for doubles (long float), %f is for float.

Noticed that too but what I didn't understand is why "%.2lf" and not just "%lf".

%.2lf should also work. The only difference is the number of decimal places that are displayed. If you don't specify like with %lf, it will display all the decimal places.