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<h1>Problems in your code</h1> Allright. Now that you've provided all the code it's easier to explain your problems: <ol> <li>You're trying to define variables "in the middle" of your functions. C doesn't allow this. you have to define all your variables right at the start. That's what's giving you the <code>error C2143: syntax error : missing ';' before 'type'</code> errors.</li> <li>Same goes for the function declaration (needs to be at the top of the function).</li> </ol> Therefore, changing your code to the following makes it work: <pre><code>#include <stdio.h> #include <stdlib.h> #include <math.h> #define ARRAY_SIZE 11 #define VECTOR_SIZE 5 main() { void f(long double fa[], long double fb[], long double fA, long double fB); long double* z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); long double* k = (long double*) malloc(sizeof (long double) * VECTOR_SIZE); int i; long double A, B; if (z == NULL) { printf("Out of memory\n"); exit(-1); } 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> <h2>A few other points</h2> Now I'll add a few more tips, that perhaps aren't strictly errors (meaning, they still compile...), but aren't very good coding practices: <ol> <li>As I said before, use <code>const</code>s to define constants rather than <code>#define</code>s.</li> <li>define <code>main()</code> properly - that is <code>int main() {...</code> rather than just <code>main()</code> without a return type. It works in C, but doesn't work in C++ and I consider it bad style. (Why the hell am I supposed to assume functions return int if nothing else is said? why not void?)</li> <li>Following that, you should explicitly return a value from <code>main()</code>.</li> <li>I prefer declaring the <code>void f(long double fa[], long double fb[], long double fA, long double fB);</code> function prototype outside <code>main()</code>.</li> <li>When defining functions use the modern syntax - the one you used in the prototype - rather than the ancient one: <code>void f(fa, fb, fA, fB)</code> <code>long double fa[], fb[], fA, fB;</code> <code>{</code> Should become: <code>void f(long double fa[], long double fb[], long double fA, long double fB) {</code>.</li> </ol> This way your code turns to: <pre><code>#include <stdio.h> #include <stdlib.h> #include <math.h> void f(long double fa[], long double fb[], long double fA, long double fB); int main() { const int ARRAY_SIZE = 11; const int VECTOR_SIZE = 5; long double* z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); long double* k = (long double*) malloc(sizeof (long double) * VECTOR_SIZE); int i; long double A, B; if (z == NULL) { printf("Out of memory\n"); exit(-1); } 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; return 0; } void f(long double fa[], long double fb[], long double fA, long double 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> Which I think is better. <h1>First Post</h1> Please provide all your code. I tested the following code on Visual C++ 2008 Express with "language extensions" disabled and level 4 warnings. It works just fine: <pre><code>#include <stdlib.h> #include <stdio.h> int main() { const int ARRAY_SIZE = 1024*1024; long double *z1 = (long double *)malloc(sizeof (long double) * ARRAY_SIZE); if (z1 == NULL) { printf("Out of memory\r\n"); exit(-1); } printf("Awesome!\r\n"); return 0; } </code></pre> Maybe you forgot an include, maybe you did something else wrong. The code snippet itself seems perfectly fine. The second error you described seems totally unrelated: <code>error C2065: 'L' : undeclared identifier // this error repeats for all my identifiers</code> By the way, prefer <code>const</code> over <code>#define</code>.
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