Difference between revisions of "Recital Flow Control and Looping"
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===Recital do while loops=== | ===Recital do while loops=== | ||
| − | The [[DO WHILE|do while]] command repeats the commands between the ''do while'' and the ''enddo'' statement, until the specified | + | The [[DO WHILE|do while]] command repeats the commands between the ''do while'' and the ''enddo'' statement, until the specified ''condition'' becomes false (.F.). |
<pre> | <pre> | ||
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</pre> | </pre> | ||
| + | Once the condition evaluates to false, Recital will skip down to the first statement following the ''enddo'' to continue execution. | ||
| − | + | If an ''exit'' statement is encountered, the loop is exited. If a ''loop'' statement is encountered, control returns to the head of the loop. | |
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'''Example''' | '''Example''' | ||
Revision as of 15:58, 14 January 2010
Contents
Recital Flow Control and Looping
Recital Conditional Statements
Recital do case statements
The do case command selects one course of action out of one or more alternatives.
do case case <condition as logical> [<commands>] [case <condition as logical> [<commands>]] [...] [otherwise [<commands>]] endcase
Each case condition is evaluated in turn. As soon as one of the conditions evaluates to true (.T.), the commands for that case are executed and any further case statements are ignored. Following execution of the commands, the program continues after the endcase statement. If an otherwise statement is present and no case condition evaluates to true, the otherwise commands are executed.
If no case condition evaluates to true, and there is no otherwise statement specified, then control skips to the next command following the endcase.
Example
The Recital if Statement
The if command processes commands based on the evaluation of a logical condition.
if <condition as logical> [elseif <condition as logical>] [else] endif
If the result of the if condition is true (.T.), then the commands that follow up to an else, elseif or endif statement are executed.
The elseif clause can be added to the control structure allowing for the testing of more than one condition. The if...endif block is now essentially the same as the do...case structure and elseif is analogous with a case statement.
The else statement is analogous with the otherwise statement. If no previous if condition or elseif condition is true, the commands following the else statement up to the endif statement are executed.
Example
Recital Looping Statements
Recital for loops
for <variable> = <start as numeric> to <end as numeric> [step <step as numeric>] [exit] [loop] next
Example
Recital do while loops
The do while command repeats the commands between the do while and the enddo statement, until the specified condition becomes false (.F.).
do while <condition as logical> [exit] [loop] enddo
Once the condition evaluates to false, Recital will skip down to the first statement following the enddo to continue execution.
If an exit statement is encountered, the loop is exited. If a loop statement is encountered, control returns to the head of the loop.
Example
Recital foreach loops
The foreach...endfor command is used to iterate over each element in an array or member in an object or associative array.
foreach <array> as <value as variable> | <array> as <key variable> => <value as variable> <statements> endfor
The array must be the name of an existing array or object. The value is a reference to be loaded with the contents of each element or member in turn. Using the <key> => <value> syntax, the member names of an object or associative array can also be accessed.
Examples
// static array numbers = array(1,2,3,4,5,6,7,8,9,10) foreach numbers as elem ? elem * elem endfor // associative array private myarray = array("Name" => "Recital", "Description" => "database") foreach myarray as key => value echo "key=" + key + " value=" + value + "\n" endfor
