Difference between revisions of "Recital Flow Control and Looping"
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===Recital foreach loops=== | ===Recital foreach loops=== | ||
| − | The FOREACH... | + | The [[FOREACH|foreach...endfor]] command is used to iterate over each element in an array or member in an object or associative array. |
<pre> | <pre> | ||
Revision as of 15:38, 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
If the specified <condition> result is .T., then all commands within the DO WHILE loop will be executed. If the specified condition returns an .F., Recital will skip down to the first statement following the ENDDO to continue execution.
Note: Use of redefined macros in the body of the loop is not supported. [edit] EXIT
If an EXIT statement is encountered then the DO WHILE loop is exited. [edit] LOOP
If a LOOP statement is encountered, then control returns to the head of the DO WHILE loop. [edit] ENDDO
The ENDDO statement terminates the DO WHILE loop. Commands within the DO WHILE must be properly nested.
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> | foreach <array> as <key> => <value> <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
