break -- terminate a loop or a
case switch prematurely
Introductionbreak terminates for, repeat, while loops, and case statements.
Call(s)
break _break()
Related
Functionscase, for, next, quit, repeat, return, while
Detailsbreak statement is equivalent to the function call
_break(). The return value is the void object of type
DOM_NULL.for, repeat, while, and case statements, the break
statement exits from the loop/switch. Execution proceeds with the next
statement after the end
clause of the loop/switch.break.break also terminates a statement sequence _stmtseq(..., break,
...).for, repeat, while, case, and _stmtseq, the break
statement has no effect._break is a function of the system kernel.
Example
1Loops are exited prematurely by break:
>> for i from 1 to 10 do
print(i);
if i = 2 then break end_if
end_for
1
2
>> delete i:
Example
2In a case
statement, all commands starting with the first matching branch are
executed:
>> x := 2:
case x
of 1 do print(1); x^2;
of 2 do print(2); x^2;
of 3 do print(3); x^2;
otherwise print(UNKNOWN)
end_case:
2
3
UNKNOWN
In the next version, break ensures that
only the statements in the matching branch are evaluated:
>> case x
of 1 do print(1); x^2; break;
of 2 do print(2); x^2; break;
of 3 do print(3); x^2; break;
otherwise print(UNKNOWN)
end_case:
2
>> delete x: