Branch: what changed
Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.
Title: Branch
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| 1 | + | A **branch**, also called **conditional** or **conditional statement**, is a [[statement]] that is executed depending on an [[expression|expression’s]] value. Usually this expression depends on the [[Program|program’s]] state. | |
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| 3 | + | ## Types of branches | |
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| 5 | + | [[Pascal]] knows two types of branches: | |
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| 7 | + | - [[If and Then|if … then …]] conditional statements, and | |
| 8 | + | - [[Case|case … of …]] statements. | |
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| 10 | + | They differ in how many alternatives can be named, how many “routes” could be taken. | |
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| 12 | + | In an `if … then …` branch there exists exactly one alternative. It is either executed or not. In conjunction with the word `else` one can specify exactly *two* “paths” with regard to program flow. Due to its binary nature, `if … then` requires a [[Boolean Expressions|Boolean expression]] to be evaluated. | |
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| 14 | + | `Case … of` on the other hand is n-ary, where n is greater than one. Unlike `if` the supplied expression the program flow depends on can (and has to) be of *any* integral type, e. g. an [[Integer|integer]] or [[Enum Type|enumeration]] (in FreePascal also [[String|strings]] are legal). | |
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| 16 | + | ## Usage | |
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| 18 | + | `Case … of` branches should be considered where appropriate since they [[Case Compiler Optimization|aide compiler optimizations]]. By using them [[FPC]] may re-arrange statements, the given alternatives, in order to optimize for speed or size. | |
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| 20 | + | ## See also | |
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| 22 | + | - [[Conditional compilation|conditional compilation]] and related compiler directives do *not* create branches | |
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| 24 | + | --- | |
| 25 | + | *From the Free Pascal wiki, page "Branch", as it stood on 2020-06-23 after a change by Kai Burghardt, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).* |