Ruby | Array bsearch_index() operation

Last Updated : 08 Jan, 2020

Array#bsearch_index() : bsearch_index() is an Array class method which finds the index of the array value that meets with the given condition. Its complexity is O(log n) where n is the array size. This method can work in both the modes – find-minimum and find-any mode.

Syntax:  Array.bsearch_index()

Parameter: 
- Arrays to search elements. 
- condition block

Return:  Index value of the array element that satisfy the given condition

Code #1 : Example for bsearch_index() method

# Ruby code for bsearch_index() method 
   
# declaring array 
a = [1, 2, 3, 4] 
   
# declaring array 
b = [111.11, 2.5, 4.3, 2.224] 
  
# array that meets the condition 
puts "search : #{a.bsearch_index {|x| x >=4 }}\n\n"
  
puts "search : #{b.bsearch_index {|x| x >=3 }}\n\n"
  
puts "search : #{a.bsearch_index {|x| x >=2 }}\n\n"
  
puts "search : #{b.bsearch_index {|x| x >=2 }}\n\n"

Output :

search : 3

search : 2

search : 1

search : 0

Code #2 : Example for bsearch_index() method

# Ruby code for bsearch_index() method 
   
# declaring array 
a = [1, 2, 3, 4] 
   
# declaring array 
b = [111.11, 2.5, 4.3, 2.224] 
  
# array that meets the condition 
puts "search : #{a.bsearch_index {|x| 1 - x / 4  }}\n\n"
  
puts "search : #{b.bsearch_index {|x| 2*x > 1 }}\n\n"