Error on selection structure

[mameemonster]

hello. i have a problem in selecting destination and time. when i select any number in destination the program always tell me that i choose number 1 (taiping). and the time it always show 1030 even i input number that is not 1. please tell me where i'm wrong here. thank you :)

#include <stdio.h>

int main ()
{
	int type, desti, time, amount, time2;
	char* bus[99];
	char* dest[99];
	double price, tprice;
	printf ("------------------------------\n");
	printf ("| Speed of Light Bus Company |\n");
	printf ("------------------------------\n\n");
	printf ("------------------------------------------------| \n");
	printf (" |Please select your preferred type of bus   | \n");
	printf (" |1. Single-decker\t\t\t     |\n");
	printf (" |2. Double-decker\t\t\t     |\n");
	printf ("------------------------------------------------| \n\n");
	printf (" >> ");
	scanf ("%d", &type);
	if (type = 1)
		printf ("\n >> You've selected single-decker type\n\n");
	else if (type = 2)
		printf ("\n >> You've selected double-decker type\n\n");
	else
		printf ("\n >> Please enter the correct number\n");
	if (type = 1)
		bus[99] = "Single-decker";
	else
		bus[99] = "Double-decker";
	printf ("-------------------------------------| \n");
	printf (" |Please choose your destination| \n");
	printf (" |1. Taiping >> RM28.30\t\t|\n");
	printf (" |2. Pulau Pinang >> RM31.20\t|\n");
	printf (" |3. Kuala Lumpur >> RM33.80\t|\n");
	printf (" |4. Alor Setar >> RM36.80\t|\n");
	printf (" |5. Kuantan >> RM16.30\t\t|\n");
	printf (" |6. Seremban >> RM27.40\t|\n");
	printf (" |7. Melaka >> RM39.50\t\t|\n");
	printf (" |8. Johor Bharu >> RM32.10\t|\n");
	printf ("-------------------------------------| \n\n");
	printf (" >> ");
	scanf ("%d", &desti);
	if (desti = 1) {
		printf ("\nYou've selected --> Taiping >> RM28.30\n");
		dest[99] = "Taiping\0";
		price = 28.30; }
	else if (desti = 2) {
		printf ("\nYou've selected --> Pulau Pinang >> RM31.20\n");
		dest[99] = "Pulau%%Pinang\0";
		price = 31.20; }
	else if (desti = 3) {
		printf ("\nYou've selected --> Kuala Lumpur >> RM33.80\n");
		dest[99] = "Kuala%%Lumpur\0";
		price = 33.80; }
	else if (desti = 4) {
		printf ("\nYou've selected --> Alor Setar >> RM36.80\n");
		dest[99] = "Alor%%Setar\0";
		price = 36.80; }
	else if (desti = 5) {
		printf ("\nYou've selected --> Kuantan >> RM16.30\n");
		dest[99] = "Kuantan\0";
		price = 16.30; }
	else if (desti = 6) {
		printf ("\nYou've selected --> Seremban >> RM27.40\n");
		dest[99] = "Seremban\0";
		price = 27.40; }
	else if (desti = 7) {
		printf ("\nYou've selected --> Melaka >> RM39.50\n");
		dest[99] = "Melaka\0";
		price = 39.50; }
	else if (desti = 8) {
		printf ("\nYou've selected --> Johor Bharu >> RM32.10\n");
		dest[99] = "Johor%%Bharu\0";
		price = 32.10; }
	else
		printf ("\nPlease enter the correct number : ");
	printf ("\nPlease enter how many ticket you want >> ");
	scanf ("%d", &amount);

	tprice = price * amount;

	printf ("--------------------------------------| \n");
	printf (" |Please choose what time you want | \n");
	printf (" |1. 1030\t\t\t   |\n");
	printf (" |2. 1430\t\t\t   |\n");
	printf (" |3. 1800\t\t\t   |\n");
	printf (" |4. 2230\t\t\t   |\n");
	printf ("--------------------------------------| \n\n");
	printf (" >> ");
	scanf ("%d", &time);
	if (time = 1)
		time2 = 1030;
	else if (time = 2)
		time2 = 1430;
	else if (time = 3)
		time2 = 1800;
	else if (time = 4)
		time2 = 2230;
	else
		printf ("\nPlease enter the correct number : ");

	printf ("\nThis is your ticket information : \n");
	printf ("Bus type : %s\n", bus[99]);
	printf ("Destination : %s\n", dest[99]);
	printf ("Total price = %0.2f \n", tprice);
	printf ("Time : %d\n", time2);
}

[Ancient Dragon]

line 19: use == (comparison) operator instead of = (assignment) operator

[Narue]

The = operator assigns while the == operator tests for equality. You're using the assignment operator for equality, and C's implicit equality rules apply. Here's an example of your code:

if (type = 1)
    bus[99] = "Single-decker";
else
    bus[99] = "Double-decker";

Here's how C is really interpreting it:

type = 1;

if (type != 0)
    bus[99] = "Single-decker";
else
    bus[99] = "Double-decker";

As you can see, that comparison will always be true because you ensure it with an assignment to 1 prior to making to comparison. The else clause will never be executed.

[mameemonster]

thank you. and i still have a problem. after input all number and after the output is out, there's an error appear that tell me debug error. why is that happening?

another question.. i would like to put a seat number in this program. and i want to loop it. then i want the program to tell me that if a seat is taken (eg seat number 1) then the program will tell that the seat is occupied. is that possible?

[Narue]

My crystal ball says that it's due to always accessing the 99th index in arrays that only have room for 99 items (ie. the last valid index is 98).

[mameemonster]

i changed to this. still error :(

#include <stdio.h>

int main ()
{
	int type, desti, time, amount;
	char* bus[55];
	char* dest[55];
	int time2;
	double price, tprice;
	printf ("------------------------------\n");
	printf ("| Speed of Light Bus Company |\n");
	printf ("------------------------------\n\n");
	printf ("------------------------------------------------| \n");
	printf (" |Please select your preferred type of bus   | \n");
	printf (" |1. Single-decker\t\t\t     |\n");
	printf (" |2. Double-decker\t\t\t     |\n");
	printf ("------------------------------------------------| \n\n");
	printf (" >> ");
	scanf ("%d", &type);
	if (type == 1)
		printf ("\n >> You've selected single-decker type\n\n");
	else if (type == 2)
		printf ("\n >> You've selected double-decker type\n\n");
	else
		printf ("\n >> Please enter the correct number\n");
	if (type = 1)
		bus[55] = "Single-decker\0";
	else
		bus[55] = "Double-decker\0";
	printf ("-------------------------------------| \n");
	printf (" |Please choose your destination| \n");
	printf (" |1. Taiping >> RM28.30\t\t|\n");
	printf (" |2. Pulau Pinang >> RM31.20\t|\n");
	printf (" |3. Kuala Lumpur >> RM33.80\t|\n");
	printf (" |4. Alor Setar >> RM36.80\t|\n");
	printf (" |5. Kuantan >> RM16.30\t\t|\n");
	printf (" |6. Seremban >> RM27.40\t|\n");
	printf (" |7. Melaka >> RM39.50\t\t|\n");
	printf (" |8. Johor Bharu >> RM32.10\t|\n");
	printf ("-------------------------------------| \n\n");
	printf (" >> ");
	scanf ("%d", &desti);
	if (desti == 1) {
		printf ("\nYou've selected --> Taiping >> RM28.30\n");
		dest[55] = "Taiping\0";
		price = 28.30; }
	else if (desti == 2) {
		printf ("\nYou've selected --> Pulau Pinang >> RM31.20\n");
		dest[55] = "Pulau Pinang\0";
		price = 31.20; }
	else if (desti == 3) {
		printf ("\nYou've selected --> Kuala Lumpur >> RM33.80\n");
		dest[55] = "Kuala Lumpur\0";
		price = 33.80; }
	else if (desti == 4) {
		printf ("\nYou've selected --> Alor Setar >> RM36.80\n");
		dest[55] = "Alor Setar\0";
		price = 36.80; }
	else if (desti == 5) {
		printf ("\nYou've selected --> Kuantan >> RM16.30\n");
		dest[55] = "Kuantan\0";
		price = 16.30; }
	else if (desti == 6) {
		printf ("\nYou've selected --> Seremban >> RM27.40\n");
		dest[55] = "Seremban\0";
		price = 27.40; }
	else if (desti == 7) {
		printf ("\nYou've selected --> Melaka >> RM39.50\n");
		dest[55] = "Melaka\0";
		price = 39.50; }
	else if (desti == 8) {
		printf ("\nYou've selected --> Johor Bharu >> RM32.10\n");
		dest[55] = "Johor Bharu\0";
		price = 32.10; }
	else
		printf ("\nPlease enter the correct number : ");
	printf ("\nPlease enter how many ticket you want >> ");
	scanf ("%d", &amount);

	tprice = price * amount;

	printf ("--------------------------------------| \n");
	printf (" |Please choose what time you want | \n");
	printf (" |1. 1030\t\t\t   |\n");
	printf (" |2. 1430\t\t\t   |\n");
	printf (" |3. 1800\t\t\t   |\n");
	printf (" |4. 2230\t\t\t   |\n");
	printf ("--------------------------------------| \n\n");
	printf (" >> ");
	scanf ("%d", &time);
	if (time == 1)
		time2 = 1030;
	else if (time == 2)
		time2 = 1430;
	else if (time == 3)
		time2 = 1800;
	else if (time == 4)
		time2 = 2230;
	else
		printf ("\nPlease enter the correct number : ");

	printf ("\nThis is your ticket information : \n");
	printf ("Bus type : %s\n", bus[55]);
	printf ("Destination : %s\n", dest[55]);
	printf ("Total price = %0.2f \n", tprice);
	printf ("Time : %d\n", time2);
}

[Narue]

You didn't fix the problem of accessing an array out of range. dest[55] is not a valid index, for example. It's also silly to declare an array and then only use one element. I think you need to study up a bit on arrays and how they work in C.

[D33wakar]

just use

char* bus
char* dest
.../*and later*/
bus="single-decker"
dest="taiping"

[mameemonster]

thank you. it works great. i'm sorry but i'm not really good in english. when i read online about array.. i understand nothing =.='' i'm sorry.

well about my question earlier.. i would like to put a seat number in this program. and i want to loop it. then i want the program to tell me that if a seat is taken (eg seat number 1) then the program will tell that the seat is occupied. is that possible?