Ruby journey (12) iterator IN RUBY

The iterator is a feature of advanced languages and is very easy to use.

For example, array Iteration
[1, 2, 3]. Each {| n | puts N. to_s}
(1. 100). Each {| n | puts N. to_s} iterates each element

String Iteration
"ABDC". each_byte {| CHR | printf "% C \ n", CHR} iterates each byte
"A \ Nb \ NC". each_line {| S | puts s} is split and iterated using linefeeds.

Use of retry:
You can use retry to return to the beginning of the iterator during iteration, for example

Isretry = False
For L In 0 .. 4
Print L
If L =   2   And Isretry = False
Isretry = True
Puts
Retry
End
End
Puts
# Output:
# 012
# 01234

Finally, we define our own while structure statement.

Def Mywhile (TJ)
Return   If   Not TJ
Yield
Retry
End
I = 0
Mywhile (I <   3 ) {Puts I. to_s; I + =   1 }