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POArray Passing in C
 

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  1. POArray Passing in C
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    <p>I'm having a problem passing an array to a function in C. I declare the array in main</p> <p>And then, inside of a function, I populate it.</p> <p>At which point I leave my function and pass the array to another function with the prototype</p> <p>And make an attempt to access the array.</p> <p>However once I am out of the initial function that populated the array, I am unable to access the array. It just returns values of 0.00000 and nan.</p> <pre><code>void ReadData(FILE *fpIn, int lines, double *pA ); void MinMaxAvg(double *pA, double *min, double *max, double *avg, int lines); int main() { FILE *fpIn = NULL; int lines = 0; double *pA = NULL; ReadData(fpIn, lines, pA); double min = 0; double max = 0; double avg = 0; MinMaxAvg(pA, &amp;min, &amp;max, &amp;avg, lines); printf("%lf %s %lf %s %lf \n", avg, " ", min, " ", max); return 0; } void ReadData(FILE *fpIn, int lines, double *pA ) { char fName[20]; scanf( "%s", fName); fpIn = fopen ( fName, "rt"); // fpIn = fopen( "test1.txt", "rt"); if ( fpIn == NULL) { printf( "Unable to open: "); exit(99); } //Gets Lines //int lines=0; char ch; while((ch=fgetc(fpIn))!=EOF) { if (ch=='\n') { lines++; } } // clearerr(fName *fpIn); fclose(fpIn); fopen(fName, "rt"); //Makes Array //double *pA; pA = (double *)malloc(lines*sizeof(double)); //Fills Array for (int i=0; i&lt;lines; i++) { fscanf(fpIn, "%lf", &amp;pA[i]); } for (int i=0; i&lt;lines; i++) { printf("%lf \n", pA[i]); } } void MinMaxAvg(double *pA, double *min, double *max, double *avg, int lines) { double total = 0; for (int i=0; i&lt;lines; i++) { if ( i==0) { *min = pA[0]; *max = pA[0]; } else { if (pA[i] &lt; *min) { *min = pA[i]; } if (pA[i] &gt; *max) { *max = pA[i]; } } total += pA[i]; } *avg = (total / (double)lines); } </code></pre> <p>Any Suggestions?</p> <p>Thanks!</p>
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    1. COThat's not an array, that's a pointer. Also, how do you "leave your function"? Do you `return pA`?
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    2. COIt's a pointer to an array. And no the function is void. I'm passing the array in by reference same as I do in the MinMaxAvg function. This worked perfect before I tried to allocate the array in the first function...
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    3. COI don't see anything wrong here. It must be something in the part you don't show us.
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      1. USKBart
 

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