怎么用malloc函数开辟一个数组指针?

int *p;
p=(int *)malloc(sizeof(int)*M);

int *i;
i=(强制类型转换)malloc（申请的空间大学)
例如:i=(int *)malloc(sizeof(*i));
sizeof:自动检测大小

#include <stdlib.h>         /* For _MAX_PATH definition */
#include <stdio.h>
#include <malloc.h>

void main( void )
{
   char *string;

   /* Allocate space for a path name */
   string = malloc( _MAX_PATH );

   // In a C++ file, explicitly cast malloc's return.  For example,
   // string = (char *)malloc( _MAX_PATH );

   if( string == NULL )
      printf( "Insufficient memory available\n" );
   else
   {
      printf( "Memory space allocated for path name\n" );
      free( string );
      printf( "Memory freed\n" );
   }
}

这样就行了