Ruby: String Operations

By Xah Lee. Date:

Substring

Substring extraction is done by appending a bracket [index,count].

#-*- coding: utf-8 -*-
# ruby

# substring
aa = "01234567"
p aa[0,2] # prints “01”. Start with index, then count of chars.

# negative index counts from end. -1 is last char.
p aa[-2,2] # prints “67”.

String Length

Length of the string is .length method.

# -*- coding: utf-8 -*-
# ruby

a="this"
p a.length # 4

String Join and Repetition

Strings can be joined by a plus sign +.

# -*- coding: utf-8 -*-
# ruby

p "this" + " that" # "this that"

String can be repeated using *.

# -*- coding: utf-8 -*-
# ruby

print "this" * 2 # thisthis

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  1. Ruby Basics
  2. Doc Lookup
  3. Print Version String
  4. Unicode 💎
  5. Quote String
  6. Quote Long String
  7. Format String
  8. String Operations
  9. True, False
  10. If Then Else
  11. Loop
  12. List
  13. Loop Thru List
  14. Hash Table
  15. Function Optional Parameter
  16. Map f to List
  17. Complex Numbers
  18. Intro to Reading Ruby Doc: What's M, C, ::, # ?
  19. Predefined Global Variables
  20. What's RVM, Gem, Rake, Bundler, RDoc, ri, irb?