Difference between revisions of "Control flow"
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| − | '''Control flow''' refers to the means for controlling the order in which sections of a [[program]] are | + | '''Control flow''' refers to the means for controlling the order in which sections of a [[program]] are [[execute]]d. |
| − | The underlying [[Central Processing Unit|CPU]]'s [[instruction set]] will have a number of '''transfer of control''' primitives: jump/branch, both un-conditional as well as [[conditional branch]]es; and [[subroutine]] calls. | + | The underlying [[Central Processing Unit|CPU]]'s [[instruction set]] will have a number of '''transfer of control''' primitives: [[jump]]/branch, both un-conditional as well as [[conditional branch]]es; and [[subroutine]] calls. |
[[Programming language]]s often add additional mechanisms, particularly '''block structures''', in which a group of instructions are treated as a unit for various control flow mechanisms (e.g. [[loop]]s, if-then-else constructs, etc). | [[Programming language]]s often add additional mechanisms, particularly '''block structures''', in which a group of instructions are treated as a unit for various control flow mechanisms (e.g. [[loop]]s, if-then-else constructs, etc). | ||
Revision as of 14:31, 13 August 2019
Control flow refers to the means for controlling the order in which sections of a program are executed.
The underlying CPU's instruction set will have a number of transfer of control primitives: jump/branch, both un-conditional as well as conditional branches; and subroutine calls.
Programming languages often add additional mechanisms, particularly block structures, in which a group of instructions are treated as a unit for various control flow mechanisms (e.g. loops, if-then-else constructs, etc).
Blocks are also often used to control the scope over which variables (particularly local variables) are accessible.
Interrupts and exceptions also divert the flow of control in a computer, but at times which are not always predictable.
