Ruby - String Length, For Loop Over Chars

String length. A string has a certain number of characters—this is its length. In Ruby we access the length property. We can use length in a for-loop or while-loop to access chars.

For most Ruby programs, using an iterator (like each_char) to access elements (like chars in a string) is best. But the length property, and a for-loop, can be used as well.

Iterator

An example program. Let us review the length property. With the string "ABC" it returns the value 3—the string has 3 characters in it.

Detail We use a for-loop over the string to iterate over the chars in forward order. We access each char by its index.

Detail We can use a while-loop to iterate over the string in a reverse (backwards) order. We begin at length minus one.

while

# An input string. value = "ABC" # Display the string. puts "VALUE:" << value puts "LENGTH:" << String(value.length) # Loop over characters in the string forwards. for i in 0..value.length - 1 puts "CHAR FORWARD:" << value[i] end # Loop over characters backwards. temp = value.length - 1 while temp >= 0 puts "CHAR BACKWARD:" <> value[temp] temp -= 1 end

VALUE:ABC LENGTH:3 CHAR FORWARD:A CHAR FORWARD:B CHAR FORWARD:C CHAR BACKWARD:C CHAR BACKWARD:B CHAR BACKWARD:A

String length is important in Ruby. This high-level language hides a lot of the complexity of things. With iterators (like each_char) we hide complexity when looping over chars.

Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.

Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.

This page was last updated on Nov 23, 2021 (image).

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