New to c++ kinda on the struggle bus | Together C & C++ | Page 1

short reef Oct 17, 2022, 8:32 PM

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Currently writing a simple code and as of right now it is getting stuck on checking if the integer is a 2 digit integer or not.

foggy fableBOT Oct 17, 2022, 8:33 PM

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drifting blaze Oct 17, 2022, 8:43 PM

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well okay few things you use printf, in c++ you generally should use std::cout

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i personally dont like do while and you can usually achieve the same thing with while
other thing is please indent your code properly since you posted a screenshot its much easier to read that way or post the code here

short reef Oct 17, 2022, 8:47 PM

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yeah I didn't know how to put the code in like other people cause Im guessing its not just copy paste

paper mesaBOT Oct 17, 2022, 8:47 PM

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How to Format Code on Discord

• type three "backticks" (not quotes/apostrophes, on QWERTY layout, left of 1-key)
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• enter your code on a new line and put another three backticks at the end

Example Input

```cpp
int main() {
return 0;
}
```

Example Output

int main() {
    return 0;
} ```

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short reef Oct 17, 2022, 8:48 PM

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#include<iostream>
using namespace std;

int
main () 
{
  int num, num2;
  
num = rand () % 10 + 1;
  
num2 = 4 * num - 20;
  
  do
    {
      
if (num < -9 || num>9)
    printf (" You entered: %d", num);
      

}
  
while (-9 <= num <= 9);
  printf (" error ");
  
  do
    {
      
if (num2 < -9 || num2 > 9)
    printf (" You entered: %d", num2);
      
    
}
  
while (-9 <= num2 <= 9);
  printf (" error ");
  
return 0;

}

drifting blaze Oct 17, 2022, 8:48 PM

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yes amazing

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now the code is very hard to read because you didnt indent and everything has a slightly different style

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#include <iostream>
using namespace std;

int main()
{
    int num, num2;

    num = rand() % 10 + 1;

    num2 = 4 * num - 20;

    do
    {

        if (num < -9 || num > 9)
            printf(" You entered: %d", num);

    }

    while (-9 <= num <= 9);
    printf(" error ");

    do
    {

        if (num2 < -9 || num2 > 9)
            printf(" You entered: %d", num2);

    }

    while (-9 <= num2 <= 9);
    printf(" error ");

    return 0;
}

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ran my autoformatter over the code and this is what i get

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now what do you actually want to do ?

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detect if the integer is larger than 9 right (or less than -9)

short reef Oct 17, 2022, 8:52 PM

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detect if the integer is 2 digit

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as of right now it just runs until line 15

drifting blaze Oct 17, 2022, 8:53 PM

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yes can you explain what rand() % 10 + 1; is doing?

short reef Oct 17, 2022, 8:53 PM

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picking a random integer from 1-10

drifting blaze Oct 17, 2022, 8:54 PM

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good, now imagine it generates 2

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you enter the first while loop

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and here we already have a problem

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-9 <= num <= 9 is not a valid c++ syntax

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you would need to do -9 <= num && num <= 9 to get the same behaviour

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but if that number was 2 then the while loop is true

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you have a while loop that does stuff infinitely because you dont change num in the while loop

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and the comparison is true

short reef Oct 17, 2022, 8:57 PM

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so would that while part have to go as an else if instead?

drifting blaze Oct 17, 2022, 8:58 PM

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if else would make more sense in this entire code

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i recommend you convert this all to if else and remove printf and instead use cout

short reef Oct 17, 2022, 9:01 PM

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ok thanks for the help i got it working now

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!solved

foggy fableBOT Oct 17, 2022, 9:01 PM

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Thank you and let us know if you have any more questions!

drifting blaze Oct 17, 2022, 9:01 PM

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short reef ok thanks for the help i got it working now

can you post it again though?

short reef Oct 17, 2022, 9:05 PM

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#include <iostream>
using namespace std;

int main()
{
    int num, num2;

    num = rand() % 10 + 1;

    num2 = 4 * num - 20;


        if (num < -9 || num > 9)
            printf(" You entered: %d", num);
            
        else if (-9 <= num && num <= 9)
            printf(" You entered: %d", num);


 

        if (num2 < -9 || num2 > 9)
            printf(" You entered: %d", num2);
        else if(-9 <= num2 && num2 <= 9)
            printf("You entered: %d", num2);


    return 0;
}

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ik it isnt proper but i now have it differentiating them and just have to right some extra code for it to function differently when given an integer that is one digit

drifting blaze Oct 17, 2022, 9:09 PM

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short reef ```cpp #include <iostream> using namespace std; int main() { int num, num2;...

well for code readability you should move your ifs a bit more to the left so that they match with num and num2, but you always print out printf("You entered: %d", num2); so whatever happens it will always print that out

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so you could remove your ifs and still have the same code

#include <iostream>
using namespace std;

int main()
{
    int num, num2;

    num = rand() % 10 + 1;

    num2 = 4 * num - 20;

    cout << "You entered: " << num << endl;

    cout << "You entered: " << num2 << endl;


    return 0;
}

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amd you shouldnt use printf in c++

short reef Oct 17, 2022, 9:14 PM

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I understand as of right now the ifs aren't required but I'm going to make it so one digits display as text. This was just the setup of that.

#New to c++ kinda on the struggle bus