Ruby - How to check string contains in an array?

Question

I want to extract a list which doesn't contain(not exact match) a word which I have given. Example:

a = ["drop", "drop down", "forum", "drop down forum"]

b = ["drop", "drop down", "forum", "drop down forum", "data"]

Input string is str = "drop"

Output should be like: a = ["forum", "data"]

It is like a "LIKE" query in MySQL but I want to do it using ruby language. Please help to solve this.

Is there any reason your example data has two arrays? Why is the output of a ["forum", "data"]? Must array b be combined with array a somehow? — 3limin4t0r
– 3limin4t0r, Commented Oct 16, 2020 at 11:09
Your title doesn't convey what you are trying to do. I think you want something like, "How to extract strings from an array that that do not contain certain words". You don't need "Ruby" in the title because "ruby" is a tag (as it must be). You don't want rails as a tag because it is a pure-Ruby question. Moreover, the other tags won't help in searches, so I suggest that "ruby" be the only tag. — Cary Swoveland
– Cary Swoveland, Commented Oct 16, 2020 at 18:38

Salil · Accepted Answer · 2020-10-16 11:15:30Z

3

Ref reject!, Deletes every element of self for which the block evaluates to true.

list = ["drop", "drop down", "forum", "drop down forum"]
str = 'drop'
list.reject!{|item| item.include? str} # list = ["forum"]

Note :- include? is case sensitive for ex:- 'Drop down'.include? 'drop' will return false.

For case insensitive we can do something like following

list.reject!{|item| item.downcase.include? str.downcase}

For multiple list you can do following

list_one = ["drop", "drop down", "forum", "drop down forum"]
list_two = ["drop", "drop down", "forum", "drop down forum", "data"]
(list_one + list_two).uniq.reject{|item| item.downcase.include? str.downcase} # ["forum", "data"]

edited Oct 16, 2020 at 11:15

answered Oct 16, 2020 at 10:46

Salil

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3 Comments

Tom Lord Over a year ago

It would help to use meaningful variable names, not a and aa. How about list and item?

Shruthi R Over a year ago

Can't we extract it by comparing 2 arrays with given string(input) ? Updated the question.

Cary Swoveland Over a year ago

What about list = ["drop", "droplet", "gumdrops"]? That's why @Sampat used a regex with word boundaries.

Sampat Badhe · Accepted Answer · 2020-10-16 15:36:03Z

1

list1 = ["drop", "drop down", "forum", "drop down forum"]

list2 = ["drop", "drop down", "forum", "drop down forum", "data"]

result = (list1 | list2).reject{ |i| i.match(/\bdrop\b/i) }
=> ["forum", "data"]

edited Oct 16, 2020 at 15:36

answered Oct 16, 2020 at 15:27

Sampat Badhe

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