PURPOSE: To improve search efficiency by switching a retrieval unit from one byte to plural bytes when the specific code in data is retrieved.
CONSTITUTION: When a code which has a meaning by using plural bytes is retrieved by the method for retrieving specific one-byte codes 2 and 3 in data 1 wherein a code having a meaning by one byte and the code having the meaning by the plural bytes are both present, the retrieval unit is switched to the plural bytes and the specific code 3 is retrieved. Thus, when the code having the meaning by the plural bytes is retrieved after the specific code 2 is retrieved, the retrieval unit is switched to the plural bytes to retrieve the specific code 3. Namely, the frequency of comparison is, for example, 12 in this case and less than when comparison is made, byte by byte, 18 times, and the retrieval efficiency is improved.
YOSHIDA MASAKI
ASAI KIYOSHI
KOIZUMI KYO
KARUUMI SATORU
