Why do numeric string comparisons give unexpected results?

Question

\'10:\' < \'1:\'
# => true

Can someone explain me why the result in the above example is true? If I just compare \'1:\' and \'2:\' I get the

Answer 1

It is character by character comparison in ASCII.

'10:' < '1:' is (49 < 49) || (48 < 58) || (58 < ?)

#=> true

'1:' < '2:' is (49 < 50) || (58 < 58)

#=> true

Left to Right boolean check is used and check breaks where true is found.

Note: It is just my observation over various example patterns.

Answer 2

The first character of each of your two strings are the same. And as Dave said in the comments, the second character of the first, '0', is less than ':', so the first string is less than the second.

Answer 3

Strings are compared character by character.

When you compare 1: vs 2:, the comparison begins with 2 vs 1, and the comparison stops there with the expected result.

When you compare 1: vs 10:, the comparison begins with 1 vs 1, and since it is a tie, the comparison moves on to the next comparison, which is : vs 0, and the comparison stops there with the result that you have found surprising (given your expectation that the integers within the strings would be compared).

To do the comparison you expect, use to_i to convert both operands to integers.

Answer 4

Because the ASCII code for 0 is 48, which is smaller than the ASCII code for :, which is 58.