[1011] <<c Language Depth analysis >> testing test

/**********************************  wzsts "C-Language depth analysis" 2016 ****                     ****   &NBSP;&NBSP;&NBSP;FUN1~FUN6 Representative 6 Chapter content  ****fun10~fun19 represents the function called by Fun1  ****                     ****       the world is fine because of the rules      ****  #if (1) can run, #if (0) does not run.  **** data  author   pc       ****16.1.1 &NBSP;&NBSP;WZ&NBSP;&NBSP;VM. centos6.5   ***********************************///the first chapter    before, then change the system lost files. Think, some things, lost, can change better! * * #include  <stdio.h> #include <string.h> #define  n  10    /*   Define allocation space, while extern and define declarations, macro substitution does not allocate space  */  #define &NBSP;EPSINON&NBSP;&NBSP;0.0001&NBSP;&NBSP;FUN0 ()    &nThe bsp; /*  function has no type, and the return value has type &NBSP;*/{&NBSP;INT&NBSP;FX=10;&NBSP;RETURN&NBSP;FX;} Void static fun ()/*  even if they are of different types, they cannot have duplicate names  */{/*  int fun =10       function name, variable name do not repeat    */}void fun10 () {int i=4;int *p=null;int a[10]={ 1,2,3,4,5};char b[ ]= "ABCDE"; char *c= "ABCDE";/*  char *c[10]= "ABCDE";     error*/char d[ ]={"ABCDE"};char e[]={' W ', ' z ', ' z ', ' x '};   if (b! =null)        if (null==c)   ;        else        printf (" c isn ' t NULL\n");   else   {     NULL;          /*  detail style to prevent mistaken  */    }printf ("*********************\n");  printf (" %d\n ", sizeof (&NBSP;&NBSP;P)  ) &NBSP;;&NBSP;&NBSP;&Nbsp;      /* 4 */printf ("%d\n", sizeof (&NBSP;*P)  )  ;          /* 4 */printf ("%d\n", sizeof ( int) *i )  ;/* 4 i=0,is 0 i=4,is 16*/printf ("*********************\n");  printf ("%d\n") , sizeof (&NBSP;&NBSP;A)  )  ;         /* 40 */ printf ("%d\n", sizeof (  a[10] )  )  ;    /* 4 */printf ("%d \ n ", sizeof (&NBSP;&NBSP;&AMP;A)  )  ;        /* 4 */ printf ("%d\n", sizeof (  &a[0])  )  ;     /* 4 */printf ("%d,%d\n", sizeof (&NBSP;&NBSP;B), strlen (b)  )  ;          /* 6,5*/printf ("%d,%d\n", sizeof (&NBSP;&NBSP;C), strlen (c)  )  ;          /* 4,5*/ printf ("%d,%d\n", sizeof (&NBSP;&AMP;C), strlen (e)  )  ;          /* 4,9*/printf ("%d,%d\n", sizeof (&NBSP;&NBSP;D), strlen (d)  )  ;          /* 6,5*/ printf ("*********************\n");  } Void fun11 () {int i=-20;unsigned j=10;float ftestval=0.0,ff=0; if (ftestval==0.0)   printf ("test 1 \n");  if ((Ftestval>=-epsinon) && (Ftestval<=epsinon))  printf (" Test 2 \n ");     ff=10000000.00+0.00000001; printf (" Test 2 is  better \n f=%f d=%d\n ", FF,FF);    /*  cannot be so transformed    */    i= (int) ff;   printf (  "f=%f d=%d\n", Ff,i);         /*    forced conversion    *///bool b;  c++//if (B==false )  ;  vc++&nbsP; medium True is 1VB in true is -1 //printf ("d=%d,u=%u\n", I+j,i+j);             /*d=-10,u=4294967286*///for (j=9;j>=0;j--)   {printf ("%u\n", j);}     /* dead loop   always print       *///for (j=9;j>=1;j--)      {printf ("%u\n", j);}   /*  modified to print 9 to 1      */    scanf ("%d\n", &i) ; switch (i)   {/******       right         ********/    case 1:printf ("case 1\n");     case 2:printf ("case 2\n");    /*******      error         *******/   // case a:printf ("Case  a\n ")       /*  case statement   should be less than 20 lines    */   &nbsP;//&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;SCANF ("%d\n", &i);           switch (i)            {            case 1:printf ("case 2.1\n");break;            case 2:printf ("case 2.2\n");break;            }    default:printf (" error\n");    /*   No, there is the default error program  break has magical   case  is integer and character expression   */    /*********  error  end  **********/    }} Void fun12 () {/*for (initial value cycle condition; Loop statement) for (i=0,j=1;i<10,j<3;i++,j++) while (loop condition) {} do{}   The program performs at least one while (loop condition) */ static int i=0; //for (; i<10;i++)    for (i=0;i<= 10;i++)           /*  semi-open half-closed writing  */    {       ;     }printf ("***************\n"), while (i) { i--;p rintf ("%d", I);} printf ("%c\n");      /*  need to memorize some special ASCII values 13&NBSP;CR enter  */printf ("* * * * \ n ");d o {printf ("%d\n ", I);}      /*   no other code outside the brackets  */while (i);p rintf ("%d\n", i);p rintf ("************** *\n ");/*** long cycle efficiency is high, the program does not modify the value of the loop variable * * Cycle to short, code clear, 3 layers within the * * die cycle is not necessarily dead, it is not necessarily useless; (test how much space the machine can open, run the program that terminates) */printf (" c\n ");d o{for ( i=0;i<5;i++)     {     printf ("*");      //  if (i==1)  goto wz;      if (i==2)         continue;  /*continue termination   This (this round) cycle */       if (i==4)     /*if (i=4) results are different */                   break;     /*break   termination   This layer loop */  }printf ("%2d", i);wz:                 /*goto  It is recommended to use less jumping out of this layer loop, also can not jump out function */printf ("%d", i);p rintf ("\ n"); i-=4;              /* easy to change the number is dead cycle printing */printf ("%2d", i) ;} while (i>0);p rintf ("\ n");p rintf ("%d\n", I);}  void fun13 () {// extern    int i;          // static    int i;// unsigned  int i;//    auto    int i;// const     int i ;//  long     int i;// short     int  i;//volatile   int i;struct{}su;printf ("%d", sizeof (SU));/*&nbsP VC&NBSP;IS&NBSP;1&NBSP;,VM&NBSP;IS&NBSP;0;*/TYPEDEF&NBSP;STRUCT{INT&NBSP;L;INT&NBSP;A[0];} type;//typedef struct{int l;int a[ ];} type;/* variable length structure   variable length array, flexible array, different compiler *///typedef struct{int l;int a[10];} type;  /*   different meanings of */enum en{a=0,b,c=100,d,e}en;union check{int i;char c;} un;un.i=1;printf ("%d\n", UN.C);                       /*01 0001->1000  Small End Storage      */printf ("%d\n",  c);p rintf ("%d\n",  sizeof (EN));                /*  is a pointer on a 32-bit machine for 4  *//* differences             Enumerations        Macros ————————————————————————————— ————————— | compile-time      | determine value     | Replace, indeterminate value | | Define constants    | more than once &NBSP;&Nbsp;|  Once a     | | Editor Debug   |   can    |   not      | | Define functions     |  not    |    can be      |*/ }void fun14 () {  auto  int a=0;  const int b=1;   Register  c=2;  int datagotfromfun0=fun0 ();p rintf ("%d\n", a);  //  printf ("%d\n", &a);    //test correctly then comment                   printf ("%d\n", printf ("%d ", a));      printf ("%d\n", printf ("%d \n", a));   /* 0    ** 0  2** 0** 3*/  printf ("%d\n", c);/* printf ("%d\n", &c);   test error so comment */     /*** static  modifier variables, functions, C + + in */  printf ("datagotfromfun0 is %d\n ", DataGotFromfun0); /***   variables, functions   names involved in English grammar */printf ("%d\n ", b);/*  b++;        const==readonly  */printf ("%d\n", sizeof (int)  )  ;/*  4 */printf ("%d\n", sizeof ( a )  )  ;/* 4 */printf ("%d\n",sizeof   a   )  ;/* 4 *//* printf ("%d\n",sizeof int  )  ;   *//*      return (a); brackets can go to           */ }    void  main () {//fun10 ();//fun11 ();//fun12 ();//fun13 ();//fun14 ( );}

[1011] <<c Language Depth analysis >> testing test