In the 2nd century CE, Sextus Pompeius Festus wrote an encyclopedic epitome of the works of Verrius Flaccus, De verborum significatu, with entries in alphabetic order. In the 1st century BC, Roman writer Varro compiled alphabetic lists of authors and titles. The poet and scholar Callimachus, who worked there, is thought to have created the world's first library catalog, known as the Pinakes, with scrolls shelved in alphabetical order of the first letter of authors' names. The first effective use of alphabetical order as a cataloging device among scholars may have been in ancient Alexandria, in the Great Library of Alexandria, which was founded around 300 BCE. Similarly, biblical authors used acrostics based on the (ordered) Hebrew alphabet. In the Book of Jeremiah, the prophet utilizes the Atbash substitution cipher, based on alphabetical order. Parts of the Bible are dated to the 7th–6th centuries BCE. However, a range of other methods of classifying and ordering material, including geographical, chronological, hierarchical and by category, were preferred over alphabetical order for centuries. The system thus tends to maximize the number of common initial letters between adjacent words.Īlphabetical order was first used in the 1st millennium BCE by Northwest Semitic scribes using the abjad system. The result of placing a set of words or strings in alphabetical order is that all of the strings beginning with the same letter are grouped together within that grouping all words beginning with the same two-letter sequence are grouped together and so on. Various conventions also exist for the handling of strings containing spaces, modified letters, such as those with diacritics, and non-letter characters such as marks of punctuation. If a position is reached where one string has no more letters to compare while the other does, then the first (shorter) string is deemed to come first in alphabetical order.Ĭapital or upper case letters are generally considered to be identical to their corresponding lower case letters for the purposes of alphabetical ordering, although conventions may be adopted to handle situations where two strings differ only in capitalization.

If the first letters are the same, then the second letters are compared, and so on. If they differ, then the string whose first letter comes earlier in the alphabet comes before the other string. To determine which of two strings of characters comes first when arranging in alphabetical order, their first letters are compared. When applied to strings or sequences that may contain digits, numbers or more elaborate types of elements, in addition to alphabetical characters, the alphabetical order is generally called a lexicographical order. In mathematics, a lexicographical order is the generalization of the alphabetical order to other data types, such as sequences of numbers or other ordered mathematical objects.

For the creation of an alphabetic writing system, which in instances of Latin script is called romanization, see Romanization.Īlphabetical order is a system whereby character strings are placed in order based on the position of the characters in the conventional ordering of an alphabet. For other uses, see Alphabetical (disambiguation).

'Alphabetical' and 'Alphabetization' redirect here.

Words spelled alphabetically