def palindrome?(str)
reversed_str = ''
i = str.length - 1
while i >= 0
reversed_str += str[i]
i -= 1
end
reversed_str == str
end
specs
describe "palindrome?" do
it "should accept a string as an arg" do
expect { palindrome?("tot") }.to_not raise_error
end
context "when the string is the same forwards and backwards" do
it "should return true" do
expect(palindrome?("tot")).to eq(true)
expect(palindrome?("racecar")).to eq(true)
expect(palindrome?("madam")).to eq(true)
expect(palindrome?("aa")).to eq(true)
expect(palindrome?("a")).to eq(true)
end
end
context "when the string is not the same forwards and backwards" do
it "should return false" do
expect(palindrome?("cat")).to eq(false)
expect(palindrome?("greek")).to eq(false)
expect(palindrome?("xabcx")).to eq(false)
end
end
it "should not use String#reverse" do
expect_any_instance_of(String).to_not receive(:reverse)
palindrome?("tot")
end
end
Top comments (1)
If this was for a test, to see if you could check whether a string was a palindrome without using an explicit
reversemethod, then I'd say it was against the spirit of the question to write your ownreversefunction. I guess it's a contrived interview type problem, and I think if I was conducting the interview I'd want to see something different.Some comments have been hidden by the post's author - find out more