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POmalloc: error checking and freeing memory
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copied!<p>I'm using malloc to make an error check of whether memory can be allocated or not for the particular array z1. ARRAY_SIZE is a predefined with a numerical value. I use casting as I've read it's safe to do so.</p> <pre><code>long double *z1 = (long double *)malloc(sizeof (long double) * ARRAY_SIZE); if(z1 == NULL){ printf("Out of memory\n"); exit(-1); } </code></pre> <p>The above is just a snippet of my code, but when I add the error checking part (contained in the if statement above), I get a lot of compile time errors with visual studio 2008. It is this error checking part that's generating all the errors. What am I doing wrong?</p> <p>On a related issue with malloc, I understand that the memory needs to be deallocated/freed after the variable/array z1 has been used. For the array z1, I use:</p> <pre><code>free(z1); z1 = NULL; </code></pre> <p>Is the second line <code>z1 = NULL</code> necessary?</p> <p>I get 102 errors...well MVS2008 stops the errors at 102. The errors are of type:</p> <pre><code>error C2143: syntax error : missing ';' before 'type' error C2065: 'L' : undeclared identifier // this error repeats for all my identifiers </code></pre> <p>and this points right after the closing } in the if statement.</p> <p>ARRAY_SIZE is quite large. I define it as</p> <pre><code>#define ARRAY_SIZE 2500001 </code></pre> <p>My full above code is too long. But I have a smaller code which is giving me the same behavior. Sorry for the formatting. I can't seem to get it right.</p> <pre><code>#include stdio.h //note I have the actual < > in my code #include stdlib.h #include math.h #define ARRAY_SIZE 11 #define VECTOR_SIZE 5 main() { long double *z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); if(z == NULL){ printf("Out of memory\n"); exit(-1); } long double *k = (long double*) malloc(sizeof (long double) * VECTOR_SIZE); int i; long double A, B; void f(long double fa[], long double fb[], long double fA, long double fB); A = 0.5; B = 2; for(i = 0; i < VECTOR_SIZE; i++){ k[i] = 0; } k[1] = 4; k[2] = 8; for(i = 0; i < ARRAY_SIZE; i++){ z[i] = 0; } z[1] = 5; f(k, z, A, B); free(z); free(k); z = NULL; k = NULL; } void f(fa, fb, fA, fB) long double fa[], fb[], fA, fB; { fa[0] = fb[1]* fA; fa[1] = fa[1] - 1; fb[0] = 2* fB - fa[2]; printf("fa[2] is 8 and is the same as *[fa + 2] and is %3.3Le\n", *(fa + 2)); printf("\nAddress of &fa[2] is %x\n", &fa[2]); printf("same address is fa + 2 is %x\n", fa + 2); return; } </code></pre>

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