### List All Prime Numbers problem

I wrote the following code to output a list of all prime numbers between 1 and 1000. It is not outputting 2 though. I understand why. The initial value of both j and i are 2 and since j is not less than i at that time, it does not show it.

Other than adding a cout << "2\t";

How can I get my code to kick out the 2, which is also prime?

 ``12345678910111213141516171819202122232425262728293031`` ``````case 'B':// Display a list of all Prime numbers between 1-1000. { system ("cls"); cout << "DISPLAYING ALL PRIME NUMBERS FROM 1-1000\n\n"; int count=1; // cout << " 2\t"; for (int i = 2; i < 1000; i++) { for (int j = 2; j < i; j++) { // cout << "j = " << j << endl; if (i % j == 0) { break; // i is NOT prime. Move on to the next number. } else if (i == j + 1) { cout << " " << i << "\t"; // Separate each number by a tab. if (count % 9 == 0) // Add CR after printing 8 numbers. { cout <<"\n"; } count++; } } } cout << "\n"; system ("pause"); } break;``````
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You could do it like this. The important change is the new variable `bool prime`. It is set false at line 18 and tested at line 23.

Apologies, i also made some minor formatting changes to suit my own preferences.
 ``12345678910111213141516171819202122232425262728293031323334353637`` ``````#include #include using namespace std; int main () { int count=1; for (int i = 2; i < 1000; i++) { bool prime = true; for (int j = 2; j < i; j++) { if (i % j == 0) { prime = false; break; // i is NOT prime. } } if (prime) { cout << setw(5) << i; if (count % 10 == 0) // CR every 10 numbers. { cout <<"\n"; } count++; } } cout << endl; cin.get(); return 0; }``````

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OK, what does the cin.get(); statement do?

I added the bool statement and it still is doing the same thing? It lists all the prime numbers from 3 to 997.
Did you try the code exactly as in my previous post?
When I run it, this is the output:
 ``` 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 101 103 107 109 113 127 131 137 139 149 151 157 163 167 173 179 181 191 193 197 199 211 223 227 229 233 239 241 251 257 263 269 271 277 281 283 293 307 311 313 317 331 337 347 349 353 359 367 373 379 383 389 397 401 409 419 421 431 433 439 443 449 457 461 463 467 479 487 491 499 503 509 521 523 541 547 557 563 569 571 577 587 593 599 601 607 613 617 619 631 641 643 647 653 659 661 673 677 683 691 701 709 719 727 733 739 743 751 757 761 769 773 787 797 809 811 821 823 827 829 839 853 857 859 863 877 881 883 887 907 911 919 929 937 941 947 953 967 971 977 983 991 997```

 What does the `cin.get();` statement do?
- that's an alternative to the use of `system("pause")` which is discussed here and elsewhere. The use of system() should be avoided.
http://www.cplusplus.com/forum/beginner/1988/
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Chervil, that works perfectly when I use your code exactly. Now that I read the attached thread, I understand the system issue. What I don't understand is that at the bottom of your code, you have cin.get(); and you said it should replace the system ("pause");. However, it does not. I read the other thread and they said to do cin.get(); cin.get();. When I use that, it works, but leaves no message on the screen telling the user what to do. I added a cout statement and resolved that.
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