Concatenation

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For concatenation of general lists, see append.

In computer programming, string concatenation is the operation of joining two character strings end to end. For example, the strings "snow" and "ball" may be concatenated to give "snowball". In many programming languages, string concatenation is a binary infix operator.

For example, the following expression uses the "+" symbol as the concatenation operator:

print "Hello " + "World";

[edit] In Telephony and Public Address

In programming for telephony, concatenation is used to provide dynamic audio feedback to a user. For example in a "time of day" speaking clock, concatenation is used to give the correct time by playing the appropriate recordings concatenated together. For example:

• "At the tone the time will be"
• "Eight"
• "Thirty Five"
• "...and twenty seconds"

The recordings themselves exist separately, but playing them one after the other provides a grammatically correct sentence to the caller.

This technique is also used in number change announcements, voice mail systems, or most any telephony application that provides dynamic feedback to the caller (e.g. moviefone, tellme, and others).

Programming for any kind of computerized public address system can also employ concatenation for dynamic public announcements (for example, flights in an airport). The system would archive recorded speech of numbers, routes or airlines, destinations, times, etc. and play them back in a specific sequence to produce a grammatically correct sentence that is announced throughout the facility.

[edit] External links

• Concatenation of languages (different from concatenation on strings)