sprintf

This is a discussion on sprintf within the C Programming forums, part of the General Programming Boards category; Hello. I have two uint8_t values that i would like to combine in a char array. I know I can ...

  1. #1
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    Talking sprintf

    Hello.

    I have two uint8_t values that i would like to combine in a char array. I know I can use sprintf to store one of them in a char array, like shown below. How do i append the other one?

    Thanks a lot for helping me out

    uint8_t adc_readingL = 174;
    uint8_t adc_readingH = 236;
    unsigned char adc_reading_chars[4];
    sprintf(adc_reading_chars, "%i", adc_readingL);

  2. #2
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    sprintf works sort of like printf, just add more %i terms

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    Thanks for the quick reply! so like this:? Also array length of 6 is sufficient, right? The values will never be above 255

    unsigned char adc_reading_chars[6];
    sprintf(adc_reading_chars, "%i", adc_readingL, "%i", adc_readingL);

  4. #4
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    If both values are at most 3 digits long, then you will need a minimum of 7 characters for your array - 3+3+1 (for the null terminating character) - in order to be safe.
    Code:
    char adc_reading_chars[7];
    sprintf(adc_reading_chars, "%i%i", adc_readingL, adc_readingL);
    "Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
    -Christopher Hitchens

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    Thanks

  6. #6
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    If your system supports "snprintf" it is safer that "sprintf".

    Tim S.

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