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 โ€œ01โ€. Start with index, then count of chars.

# negative index counts from end. -1 is last char.
p aa[-2,2] # prints โ€œ67โ€.

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 ๐Ÿ’Ž
  5. Quote String
  6. Quote Long String
  7. Format String
  8. String Operations
  9. True, False
  10. โ€œif then elseโ€
  11. for, while, 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?