1...3 Need Some Help

Question

Explain why it doesn't print 1,2,3 but it prints 1...3, it was like that in the lesson

print(1...3)
By the lesson, it should print 1,2,3
Please explain how it works
Thanks!

Answer 1

In which language?

Answer 2

for($i=0;(!$i%2)&&($i<4);$i++;)
echo '...😽' ;

Answer 3

That’s Swift