For example, if you had a batch file called stuff.bat and you typed stuff a b c d at the command prompt, the letters a, b, c, and d would be assigned to the variables %1, %2, %3, and %4, respectively.
Fiberglass shingles generally have a longer life expectancy than do asphalt shingles. Properly installed tiled roofs have a normal useful life of 20-30 years or longer, but individual pieces can become cracked or broken or the nails rust out.
ANSWER: The average life of a typical asphalt shingle roof is 20 years, according to Dean Morekas, home inspector with Boswell Building Surveys Inc. However, he cautioned that the life expectancy can be significantly reduced if attic ventilation is poor or if there are multiple layers of shingles.