Constant or The Constant may refer to:
Constantí is a town in the province of Tarragona and autonomous community of Catalonia, Spain.
Archaeological remains can determine that it was inhabited during the time of the Romans.
The medieval village was established in 1153, after the conquest of Siurana. Was granted a town charter in 1159. Archbishop Espàrec de la Barca (1215) boosted its population, ordering build the castle, the first church and the city wall. The castle became the summer residence of the Archbishops of Tarragona.
Had suffered several attacks during the Catalan Revolt. On January 12, 1641 the town was attacked by the troops of Josep Margarit. In 1642 was attacked by Marshal La Mothe that turned the people as a base of operations. In 1649, after a siege of two days, the city fell to the troops of Juan de Garay. The church and castle were destroyed.
During the Independence War, General Louis-Gabriel Suchet had managed from Constantí the siege of Tarragona in 1811.
In computer programming, a constant is an identifier with an associated value which cannot be altered by the program during normal execution – the value is constant. This is contrasted with a variable, which is an identifier with a value that can be changed during normal execution – the value is variable. Constants are useful for both programmers and compilers: for programmers they are a form of self-documenting code and allow reasoning about correctness; while for compilers they allow compile-time and run-time checks that constancy assumptions are not violated, and allow or simplify some compiler optimizations.
There are various specific realizations of the general notion of a constant, with subtle distinctions that are often overlooked. The most significant are: compile-time (statically-valued) constants, run-time (dynamically-valued) constants, immutable objects, and constant types (const).
Typical examples of compile-time constants include mathematical constants, values from standards (here maximum transmission unit), or internal configuration values (here characters per line), such as these C examples: