Common errors

• Dereferencing a null pointer. Segmentation fault (core dumped)
  
• Array index error: A[10]. An unrelated variable changes value, with
  unpredictable consequences.
  
• if (x=0). Assigns 0 to x, and takes false branch.
  
• Missing arguments to procedures: strcmp(buffer).
  
• Missing declarations: sin(x) without #include <math.h>.
  
• Semicolon at end of procedure or function header:
  
  myproc(int a, int b, int c);
  {
  }
  
  Causes a million syntax errors.
  
• Referring to math library routines without loading the math library.
  Compile or load command must end with -lm.
  
• Forgetting to declare types of arguments.
  
• No ``then'' keyword with ``if''.
  
• If-else statements must have BOTH parts end with semicolons.
  
• if (x==0) statement, NOT if x==0 statement .
  
• C source filename must have ``.c'' suffix
  
• Use double quotes ("), not single quotes to denote char strings