Thread: Noob question for random number

  1. #1
    Registered User
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    Noob question for random number

    Ok, I'm new to c++, I'm trying to make my second program. And I would like to know what is the c++ operation to get a random number. Can you help me??

    And as we are there, can you give it to me in a usefull syntax??

    Like can you tell me how to get:

    x = ( random number between 1 and 10 )

  2. #2
    alkis_y3k
    Guest
    This might not be the precise syntax, but:
    Code:
    int h = rand() % 100;
    This will generate a 'fake' random number from 1 to 100 i think. However, I could be mistaken. Anyone?

  3. #3
    Code Goddess Prelude's Avatar
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    > x = ( random number between 1 and 10 )
    int x = (int)( (double)rand() * 10 / RAND_MAX + 1 );

    >This will generate a 'fake' random number from 1 to 100 i think.
    From 0 to 99.

    >int h = rand() % 100;
    This is a bad way to get a random number for reasons which I've stated many times before, do a board search for more details.

    -Prelude
    My best code is written with the delete key.

  4. #4
    Senior Member joshdick's Avatar
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    Originally posted by alkis_y3k
    This might not be the precise syntax, but:
    Code:
    int h = rand() % 100;
    This will generate a 'fake' random number from 1 to 100 i think. However, I could be mistaken. Anyone?
    You're a little off, there. The code u gave will generate a random number from 0 to 99.

    SKINp, do a search of this board for random numbers. You should be able to find tons of threads on generating random numbers within certain bounds and using your computer's internal clock to make the pseudo-random numbers seem more random.
    FAQ

    "The computer programmer is a creator of universes for which he alone is responsible. Universes of virtually unlimited complexity can be created in the form of computer programs." -- Joseph Weizenbaum.

    "If you cannot grok the overall structure of a program while taking a shower, you are not ready to code it." -- Richard Pattis.

  5. #5
    If you would like true random numbers and have alot of money, I bet the people at LavaRand would be glad to make you a setup.

  6. #6
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    Hee in each of your way, I get an error telling me:

    implicit declaration of fonction 'int rand(...)'

  7. #7
    Make sure to include stdlib.h.

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