Thread: if else switch ????? which one ?

please run this simple program......

why wont this work ?

i tried it first with if...else

Code:

/*why will this program not run? what did i do wrong with the if else statements/conditions ?*/



#include <conio.h>
#include <iostream.h>
main()
{
	double sales, sales_amount, quantity, total_sales, vat;
   total_sales = sales + vat;
   vat = 0.175*sales;

   cout << "\nTotal Sales = sales amount * quantity\n";  endl;
   cout << "\nEnter the sales amount\n";
   cin >>  sales_amount;
   cout << "\nEnter the quantity\n" ;
   cin >>  quantity ;
   sales = (sales_amount * quantity);
   cout << "\n" << sales_amount << "  *  " << quantity << " = " << sales << "\n";
   cout << "\n" << "Sales is: \t" << sales << "\n";
   cout << "\ntotal sales inc VAT is: \t" << (sales + 0.175*sales) << "\n";

   	if (sales < 25) cout << "\nNo commission";                                         //<-------------why will this not run?
      else if (50 > sales < 25) cout << "\n 5% commission   " << total_sales * 0.05;
      else if (75>sales<51) cout << "\n 10% commission    "; << total_sales * 0.10;
      else if (100>sales<76)cout << "\n 20% commission"; << total_sales * 0.20;
      else cout << "20% commission" ;
   getch();

   }

i tried it with a switch statement

Code:

#include <conio.h>
#include <iostream.h>
main()
{
	double sales, sales_amount, quantity, total_sales, vat;
   total_sales = sales + vat;
   vat = 0.175*sales;

   cout << "\nTotal Sales = sales amount * quantity\n";  endl;
   cout << "\nEnter the sales amount\n";
   cin >>  sales_amount;
   cout << "\nEnter the quantity\n" ;
   cin >>  quantity ;
   sales = (sales_amount * quantity);
   cout << "\n" << sales_amount << "  *  " << quantity << " = " << sales << "\n";
   cout << "\n" << "Sales is: \t" << sales << "\n";
   cout << "\ntotal sales inc VAT is: \t" << (sales + 0.175*sales) << "\n";

   switch(sales) {
   	case <25:
      	cout << "\nNo commission";
         break;
      case 50 > sales < 25:
         cout << "\n 5% commission   " << total_sales * 0.05;
         break;
      case 75 > sales < 51:
      	cout << "\n 10% commission    "; << total_sales * 0.10;
      case 100 > sales < 76:
      	cout << "\n 20% commission"; << total_sales * 0.20;
      default:
      	cout << "\n 20% commission";
   }
   getch();
}

someone help me out please...

Originally Posted by iMalc

Try and read expression such as this

Code:

50 > sales < 25

aloud to yourself.

You may find yourself wanting to use the word "between", but there is no such operator as "between". You have to read < as "less-than" and > as "greater-than" etc.

You'll probably also find yourself wanting to use the word "and" in your description, but this does not match what you wrote because there was no && (read as "and") in that expression.
This actually indicates what the mistake is. You do have two conditions there, so using an && is actually necessary.
It should read as:
"sales is greater-than 25 AND sales is less-than 50".
Why do we have to mention sales twice? Because you have to be able to break up ANDed expressions into individual expressions and "is less than 50" is not valid as nobody would know what you are talking about.

You cannot use double in a switch.
Lastly, what happens if sales comes out to exactly 25 or exactly 50?!

i tried tjis and it works better. Thanks

Code:

#include <conio.h>
#include <iostream>

int main()
{
	double sales, sales_amount, quantity, total_sales, vat;
	total_sales = sales + vat;
	vat = 0.175*sales;

	cout << "\nTotal Sales = sales amount * quantity\n" << endl;
	cout << "\nEnter the sales amount\n";
	cin >>  sales_amount;
	cout << "\nEnter the quantity\n" ;
	cin >>  quantity ;
	sales = (sales_amount * quantity);
	cout << "\n" << sales_amount << "  *  " << quantity << " = " << sales << "\n";
	cout << "\n" << "Sales is: \t" << sales << "\n";
   total_sales = (sales + 0.175 * sales);
	cout << "\ntotal sales inc VAT is: \t" << total_sales << "\n";

	if(total_sales<25)
		cout << "\nNo commission";                                         //<-------------why will this not run?
	else if(total_sales<50)
		cout << "\n5% commission of total sales is " << 0.05 * total_sales;
	else if(total_sales<75)
		cout << "\n10% commission of total sales is " << 0.10 * total_sales;
	else if(total_sales>75)
		cout << "\n20% commission of total sales is " << 0.20 * total_sales;
	getch();

}