1.1.2 Basic of C and C++

• C++ inherited basic data type, variable name, statement, expression, and operator, control flow, function, file, head file and library, array, pointer and structure from C language. C++ is subset of C, so any C programmes can be compiled by C++.
• Duration and scope are two different conceptions. there are three durations 1)automatic 2)static and 3)dynamic. there are three scopes 1) global 2) file(translation unit) and 3) local. In C++, We can use namespace to add another more scopes.
• Compared with C language, C++ include two extensions, one is template, one is OOP.
• Prefer Preincrement (++i), especially in for loop. When you use ++i or i++ inside expression, there are differences. Otherwise, there is no differences.
• How to understand *p++?
  1) Precedence of prefix ++ and * is same. Associativity of both is right to left.
  2) Precedence of postfix ++ is higher than both * and prefix ++. Associativity of postfix ++ is left to right.
  for(int i = 0;i<10; ++i) 
  j=++i; // j = i+1; 
  j=i++; //j = i;  i=i+1; 
  //when i++ used in expression. it can be 
  //treated as two statments; 
  //same idea *p++; 
  *p++; // *(p++);  *p ; p=p+1; 
  ++*p;  //++(*p) ; 
  *++p; //*(++p);