Issues a distinction: null NULL 0 nullptr a - 1 2 distinction and use: ASCII UTF8 the UNICODE . 3 int : original code, the inverted complement code . 4 a float : index storage, stores decimal 5 Calculated: Size after alignment structure HTTPS: // WWW .cnblogs.com / Clover-TOEIC / P / 3853132.html . 6 pretreatment: typedef HTTPS: // www.cnblogs.com/csyisong/archive/2009/01/09/1372363.html . 7 pretreatment: #pragma Once HTTPS : // www.cnblogs.com/Braveliu/archive/2012/12/29/2838726.html . 8 pretreatment: #ifndef HTTPS: // www.cnblogs.com/clover-toeic/p/3851102.html 9 Design: unlimited pass function parameters (printf / scanf) HTTPS: // www.cnblogs.com/clover-toeic/p/3736748.html 10 C language function call stack (a) HTTPS: // www.cnblogs.com/ TOEIC-Clover / the p-/ 3755401.html 11 C language function call stack (two) HTTPS: // www.cnblogs.com/clover-toeic/p/3756668.html 12 Zoning: several partitions, each space has a maximum how much HTTPS: // www.cnblogs.com/southcyy/p/10167005.html HTTPS: // blog.csdn.net/yangquanhui1991/article/details/51786380 HTTPS: // blog.csdn.net/subo86/article/details / 4814874 HTTPS: //blog.csdn.net/daiyutage/article/details/8605580 12 C language header file organization and the principles contained HTTPS: // www.cnblogs.com/clover-toeic/p/3728026.html 13 design printed log and debugging (error information) Assert Assert (FALSE); the printf ( " % S \ n-% S \ n-% S \ n-% D \ n- " , __DATE__, __FILE__, __func__ in, __LINE__); 14 pointer concept: the pointer array, the array pointer, pointer constant , constant pointer, pointer functions, function pointers, complex combinations, two pointer, three pointer 15 document literacy: RB and r wb and W 16 macro functions: write more complex macro functions #define . 17 read-only setting: global, parameter 1 recursively solving practical problems 2 hardcoded