Thread: int data type past 32767 in program no error received (program runs)

  1. #1
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    int data type past 32767 in program no error received (program runs)

    Hey all, i'm working on a programming question from a website. The question requires me to use a Fibonacci sequence whose values do not exceed four million. My question, to prepare me for the Fibonacci problem, data types:


    int signed -32,76 - +32,767
    unsigned long 0 - 4,294,967,295


    I wrote a quick program, below, with values of int outside of the specified range (-32,767 - +32,767) for int and the program ran & successfully (4000000 was reached). Was wondering what if any error I can expect (any compiler errors initializing a variable that is out of data type size?)


    Code:
    #include <stdio.h>
    
    
    int main (void)
    {
            int limit = 4000000;
            int i = 3500000;
    
    
    
    
            while (i < limit)
            {
                    i++;
                    printf("%d\n", i);
            };
    
    
            return 0;
    }

  2. #2
    Registered User
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    Dec 2017
    Posts
    930
    The range of [-32,767, +32,767] for an int is only the minimum range guaranteed by the standard. It would only usually be that limited on a 16-bit system. (And even there the lowest value would be -32,768 for a two's complement machine.)

    Try running this on your system.
    Code:
    #include <stdio.h>
    #include <limits.h>
     
    int main() {
        printf("SHRT_MIN:    %20d\n",   SHRT_MIN);
        printf("SHRT_MAX:    %20d\n",   SHRT_MAX);
        printf("USHRT_MAX:   %20u\n",   USHRT_MAX);
        printf("INT_MIN:     %20d\n",   INT_MIN);
        printf("INT_MAX:     %20d\n",   INT_MAX);
        printf("UINT_MAX:    %20u\n",   UINT_MAX);
        printf("LONG_MIN:    %20ld\n",  LONG_MIN);
        printf("LONG_MAX:    %20ld\n",  LONG_MAX);
        printf("ULONG_MAX:   %20lu\n",  ULONG_MAX);
        printf("LLONG_MIN:   %20lld\n", LLONG_MIN);
        printf("LLONG_MAX:   %20lld\n", LLONG_MAX);
        printf("ULLONG_MAX:  %20llu\n", ULLONG_MAX);
        return 0;
    }
    I get:
    Code:
    SHRT_MIN:                  -32768
    SHRT_MAX:                   32767
    USHRT_MAX:                  65535
    INT_MIN:              -2147483648
    INT_MAX:               2147483647
    UINT_MAX:              4294967295
    LONG_MIN:    -9223372036854775808
    LONG_MAX:     9223372036854775807
    ULONG_MAX:   18446744073709551615
    LLONG_MIN:   -9223372036854775808
    LLONG_MAX:    9223372036854775807
    ULLONG_MAX:  18446744073709551615
    Last edited by john.c; 01-25-2020 at 05:20 PM.
    If you want the truth to stand clear before you, never be for or against. - Sent-ts'an

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