CODEWITHSUNDEEP
javascriptstring
Robert
Robert

Reputation: 10400

javascript comparison of strings

I have the following script

document.write("12" < "2");

which returns true. Any reason why? The documentation says that javascript compares strings numerically but, I don't see how "12" is less than "2".

Upvotes: 4

Views: 2811

Answers (4)

csuwldcat
csuwldcat

Reputation: 8249

I believe it is doing a lexicographic comparison - the first char in string one is '1', which is less than the first char of string two, which is '2'. More about Lexicographic order here: http://en.wikipedia.org/wiki/Lexicographical_order

Upvotes: 5

BuDen
BuDen

Reputation: 927

Try:

document.write(parseInt("12") < parseInt("2"));

Upvotes: -2

David Thomas
David Thomas

Reputation: 253506

This is because the first character of "12" is 1, which comes before "2"; and JavaScript string comparison is lexically/alphabetically, rather than numerically. Though it appears partially numeric, since 1 is sorted ahead of 2.

You can, however, simply compare the numbers as numbers:

document.write(parseFloat("12") < parseFloat("2"));

Upvotes: 3

Quentin
Quentin

Reputation: 944534

JavaScript compares strings character by character until one of the characters is different.

1 is less than 2 so it stops comparing after the first character.

Upvotes: 10

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