Solution to TEST in D

[movax]

import std.stdio;
import std.cstream : din;
int main(char[][] args) {
  int a;
  while (din.readf(&a)) {
    if (a == 42) break;
    writefln(a);
  }
  return 0;
}

or with C-like style:

import std.c.stdio : scanf, printf;
int main(char[][] args) {
  int a;
  while (scanf("%d\n\0", &a)) {
    if (a == 42) break;
    printf("%d\n\0", a);
  }
  return 0;
}

[Nguyen_Ha_Duong]

import std.cstream;
int main() {
    int n;
    din.readf(&n);
    while (n != 42) {
        dout.writef(n, "\n");
        din.readf(&n);
    }
    return 0;
}

Or

import std.stdio;
int main() {
    int n;
    scanf("%d", &n);
    while (n != 42) {
        writefln(n);
        scanf("%d", &n);
    }
    return 0;
}