(Data Processing)

[margeinchargexo]

Okay, so I need some serious help! This is due tomorrow, and I've been breaking my head trying to figure this out for the past 3 days and I just can't deal with it anymore. I'm usually okay with C++, but this is impossible for me right now. Can someone please help! I can do part a, but parts b and c are my problem. I really appreciate the help!

3. (Data Processing)
a. Write a program to display the following two prompts:

Enter a month (use a 1 for Jan, etc.):
Enter a day of the month:

Have your program accept and store a number in the variable month in response to the first prompt and accept and store a number in the variable day in response to the second prompt. If the month entered is not between 1 and 12, print a message informing the user that an invalid month has been entered. If the day entered is not between 1 and 31, print a message informing the user that an invalid day has been entered.

b. What will your program do if the user enters a number with a decimal point for the month? How can you make sure your if statements check for an integer number?

c. In a non-leap year, February has 28 days; the months January, March, May, July, August, October, and December have 31 days; and all other months have 30 days. Using this information, modify the program written in Exercise 3a to display a message when an invalid day is entered for a user-entered month. For this program, ignore leap years.

[LB]

Where are you stuck? Parts A and C seem the easiest to do ;)

[margeinchargexo]

Hi LB, I did part a. Part b is confusing me because I am not sure how to keep the user from entering a decimal. Is there a specific code that checks for an integer number? Part c is just too confusing as a whole. Maybe I've been trying to figure it out for so long that my brain has stopped working, I don't know. But it's too complex, for lack of a better word, for me to deal with it.

[ResidentBiscuit]

Cin will raise a flag if a user tries to input some data that doesn't correspond with the variable. Look up these flags and how to check for them

[LB]

Our residential biscuit has told you about how cin doesn't like wrong input. Normally you can do things like if(!(cin >> myvar)) which will run the code if cin didn't like the input. make sure you ingore the input and clear the error sate.

Part c is a simple switch-case structure with case fallthrough, something like:

int max;
switch(month)
{
case 2 /*Feb*/:
    max = 28;
    break;
case 1 /*Jan*/:
case 3 /*Mar*/;
//same for May, Jul, Aug, Oct, and Dec...
    max = 31;
    break;
default /*all other months*/:
    max = 30;
}
if(day > max)
{
    //report to user
}

[westbrook]

Well, for c, use if and similar statements to say, if the month equals 2, make the limit = 28, and use the or comparison to make it make the limit 30 for certain months, and 31 for others. Can you do that?

I'm not sure about b, I might know, but I don't want to give the wrong answer. Can someone tell him it?

[margeinchargexo]

Ok, so don't laugh at me, but from what you gave me, this is what I've got:
It's not running to say the least.


#include<iostream>
using namespace std;

int main()
{
double month, day, max;

cout<< "Enter a month (use a 1 for Jan, etc.):" <<endl;
cin>> month;
cout<< "Enter a day of the month:"<< endl;
cin>> day;

if (month>12)
{
cout<< "That is an invalid month."<< endl;
}
if (month<=0)
{
cout<< "That is an invalid month."<< endl;
}
if (day<=0)
{
cout<< "That is an invalid day."<< endl;
}
if (day>=32)
{
cout<< "That is an invalid day."<< endl;
}
switch(month)
{
case 2:
max = 28;
break;
case 1:
max = 31;
break;
case 3:
max = 31;
break;
case 5:
max = 31;
break;
case 7:
max = 31;
break;
case 8:
max = 31;
break;
case 10:
max = 31;
break;
case 12:
max = 31;
break;
default:
max = 30;
}
if(day > max)
{
cout<< "..."<< endl;
}
else
cout<< "Thank you."<< endl;
return 0;
}

[westbrook]

I think the main reason is that the month variable is a double. It should be an int type, as well as all the others. If I'm wrong, can someone correct me?

[ResidentBiscuit]

Our residential biscuit

Made me chuckle

Anywho, yea why are you using double? No need for any floating point numbers.
If you haven't looked into enums, this would be a good situation to learn about them :D They're not complicated at all really

Now what problems are you getting? From the looks of it, you're only gonna get a friendly "Thank you" at the end, or a mysterious "..." at the end.

if (day>=32) This is wrong. As far as I know, no month will ever have 32 days. At least with the current Gregorian calendar.

case 2:
max = 28;

Also wrong, as we see today. Albeit, 75% of the time this is alright


This code could use quite a bit of cleaning up, but let's get it working first. Tell us what issue exactly you're having.

[margeinchargexo]

Ok, my first issue is:
I don't know how to combine if statements. As you can see, I wrote 4 separate statements when I could have combined them into 2.
My second issue is, I don't fully comprehend how to have 'cin' check to see that the number the user enters is an integer instead of a decimal.
My last issue is, I just don't know how to use the switch command. I'm making it more complicated than it has to be. Now, because of that, I am not able to do part 'c' of my problem.

[ResidentBiscuit]

Look up the or/and Boolean operators. This will help a lot with cutting up repeated code.
http://www.cplusplus.com/reference/iostream/ios/good/
There's the input flag you're looking for