Pascal (unit) dB SPL, or 20 µPa. The airtightness of buildings is measured at 50 Pa. The units of atmospheric pressure commonly used in meteorology were formerly the bar, which was close to the average air pressure on Earth, and the millibar. Since the introduction of SI units, meteorologists generally measure pressures in hectopascals (hPa) unit, equal to 100 pascals or 1 millibar. Exceptions include Canada, which use kilopascals (kPa). In many other fields of science, the SI is preferred, which means Pa with a prefix (in multiples of 1000) is preferred. Many countries also use the millibars. In practically all other
Pascal (programming language) R. Hoare. Pascal programs start with the program keyword with a list of external file descriptors as parameters<ref name="iso/iec 7185:1990 6.10">Pascal ISO 7185:1990 6.10</ref> (not required in Turbo Pascal etc.); then follows the main block bracketed by the begin and end keywords. Semicolons separate statements, and the full stop (i.e., a period) ends the whole program (or "unit"). Letter case is ignored in Pascal source. Here is an example of the source code in use for a very simple "Hello world" program: A type in Pascal, and in several other popular programming languages, defines a variable in such a way