B (programming language): Difference between revisions

Revision as of 07:33, 14 June 2024

Revision as of 23:03, 17 August 2024

Line 83:

/* 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 ASCIIANSCII character set, the digits 0 to 9 have sequential

code values. */

printn(n, b) {

extrn putchar;

auto a;

/* Wikipedia note: the auto keyword 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');

}

</syntaxhighlight>

Line 102:

/* 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 conversionconver-

sion 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--;

}

while(col<2*n) {

putchar(c+'0');

a = n+1;

if(!(++col%5))

c = i = 0;

putchar(col%50?' ': '*n');

while(i<n) {

}

c =+ v[i] *10;

putchar('*n*n');

v[i++] = c%a;

c =/ a--;

}

putchar(c+'0');

if(!(++col%5))

putchar(col%50?' ': '*n');

}

putchar('*n*n');

}

v[2000];

n 2000;