Ruby and rails

1, string, which is similar to a character array

2. About [M. N] and [M... n]

ClassTestruby <test: Unit: testcase

Atog = ['A', 'B', 'C', 'D', 'E', 'F', 'G']

DefTest_sub_array

Assert atog [2,4]. Length =4

End

DefTest_sub_array_close

Assert atog [2..4]. Length =3

End

DefTest_sub_array_open

Assert atog [2...4]. Length =2

End

End

The ruby language also hinders productivity, although small;

1. Can you remember [M .. n] and [M .. n] which include N and which does not include n?

2. Are you sure you don't shake your hands when coding? Are you sure you have the wrong decimal point?

Of course, there are not many areas in the array range, or you have a unit test to escort, basically there is no impact

But I always think it can provide more obvious methods.

1. For example, the differences between [M.. N), [M. N], (M. N], and so on are not obvious.

2. Only one of them is supported. To express another meaning, you only need to add or subtract 1 when passing the parameter n.

 

Avoid it as much as possible in the future