I very confuse of tabe, only the 3rd can be skiped.

["GHui" <ugiwgh@...>]

I very confuse of tabe, only the 3rd can be skiped. 

The test as following:

> d={}

> d[1]=1

> d[2]=2

> d[3]=3

> d[5]=5

> print(#d)

3

> a={}

> a[1]=1

> a[3]=3

> print(#a)

1

> b={}

> b[1]=1

> b[2]=2

> b[4]=4

> print(#b)

4