B語言 - 维基百科，自由的百科全书

/* The following function will print a non-negative number, n, to    the base b, where 2<=b<=10.  This routine uses the fact that    in the ASCII character set, the digits 0 to 9 have sequential    code values.  */  printn(n, b) {     extrn putchar;     auto a;     /* Wikipedia note: auto declares a variable with automatic        storage (lifetime is function scope), not "automatic typing"        as in C++11. */      if (a = n / b) /* assignment, not test for equality */         printn(a, b); /* recursive */     putchar(n % b + '0'); } 

/* The following program will calculate the constant e-2 to about    4000 decimal digits, and print it 50 characters to the line in    groups of 5 characters.  The method is simple output conversion    of the expansion      1/2! + 1/3! + ... = .111....    where the bases of the digits are 2, 3, 4, . . . */  main() {     extrn putchar, n, v;     auto i, c, col, a;      i = col = 0;     while(i<n)         v[i++] = 1;     while(col<2*n) {         a = n+1 ;         c = i = 0;         while (i<n) {             c =+ v[i] *10;             v[i++]  = c%a;             c =/ a--;         }         putchar(c+'0');         if(!(++col%5))             putchar(col%50?' ': '*n');     }     putchar('*n*n'); } v[2000]; n 2000;