Control Structures: Difference between revisions
imported>StDoodle m moved Control structures to Control Structures: standards, man |
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== if/else == | == if/else == | ||
if (boolean) | if (boolean) | ||
{} | {} | ||
else if (boolean) | else if (boolean) | ||
{} | {} | ||
else | else | ||
{} | {} | ||
== switch == | == switch == | ||
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== while == | == while == | ||
while (boolean) | while (boolean) | ||
{} | {} | ||
== repeat until == | == repeat until == | ||
repeat | repeat | ||
{} | {} | ||
until (boolean); | until (boolean); | ||
== for == | == for == | ||
for x from a to b by c | for x from a to b by c | ||
is the general case. You don't need to specify whether it's going up or down - although doing so by using upto or downto does allow a runtime check to make sure you didn't screw up. | is the general case. You don't need to specify whether it's going up or down - although doing so by using upto or downto does allow a runtime check to make sure you didn't screw up. | ||
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== foreach == | == foreach == | ||
foreach x in map | foreach x in map | ||
{} | {} | ||
"map" must be an aggregate - a map or a slice. x takes on each value of the map index in turn. If there is more than one index, x iterates over the first index. | "map" must be an aggregate - a map or a slice. x takes on each value of the map index in turn. If there is more than one index, x iterates over the first index. |
Revision as of 21:18, 13 March 2010
if/else
if (boolean) {} else if (boolean) {} else {}
switch
switch (value) { case expression: statement statement ... break; default: statement statement ... break; }
while
while (boolean) {}
repeat until
repeat {} until (boolean);
for
for x from a to b by c
is the general case. You don't need to specify whether it's going up or down - although doing so by using upto or downto does allow a runtime check to make sure you didn't screw up.
If you don't specify "c", it defaults to incrementing/decrementing by 1. The first iteration is at a and the last is at b (that is to say, it goes from a to b, inclusive).
foreach
foreach x in map {}
"map" must be an aggregate - a map or a slice. x takes on each value of the map index in turn. If there is more than one index, x iterates over the first index.
For example:
boolean [int][string] map; map[15]["test"] = true; foreach int_index in map { print(int_index); //this will print '15' once, since there is only one valid value for this index foreach string_index in map[int_index] //this iterates over the "slice" of the map where 1 is fixed as the index { print(string_index); //This will print "test" once, since there is only one valid value for this index print(map[int_index][string_index]); //this will print "true" } }
So the output is
15 test true
Note that instead of nesting foreach statements, for a multidimensional map, two iterators can be used inline.
foreach x,y in map
is identical to
foreach x in map { foreach y in map[x] }
See http://kolmafia.sourceforge.net/advanced.html#maps for more details on maps.
continue/break
Like many languages with looping structures, ASH supports the break and continue statements. All looping structures (for, while, repeat until, and foreach) support these statements.
break;
Breaks out of the smallest enclosing loop. In a switch statement, breaks out of the switch statement. Execution resumes at the first statement after the end of the loop/switch statement.
continue;
Continues on to the next iteration of the loop (skipping any statments in this iteration that occur after the continue statement). In a switch statement, continue is allowed iff the switch is inside a loop, and acts as any other continue.