Loops

Syntax#

for (variable identifier in iterating collection) { expression }
while (condition) { expression }
do { expression } while (condition);
break;
continue;

For

For-loops iterate over an iterating collection. An iterating collection is any class which structurally unifies with Iterator<T> or Iterable<T> types from the Haxe standard library.

A for-loop which logs numbers in range 0 to 10 (exclusive) can be written as follows:

for (i in 0...10) {
    trace(i);
}

The variable identifier i holds the individual value of elements in the iterating collection. This behaviour is similar to for-each in other languages.

A for-loop which logs elements in an array can therefore be written as follows:

for (char in ['a', 'b', 'c', 'd']) {
    trace(char);
}

Try the example on try.haxe.org.

References

While

While-loops execute a body expression as long as the loop condition evaluates to true.

A while-loop which logs numbers in range 9 to 0 (inclusive) can be written as follows:

var i = 10;
while (i-- > 0) {
    trace(i);
}

Try the example on try.haxe.org.

References

“While”, Haxe manual

Do-while

Do-while-loops execute a body expression at least once, and then keep executing it as long as the loop condition evaluates to true.

A do-while-loop which logs numbers in range 10 to 0 (inclusive) can be written as follows:

var i = 10;
do {
    trace(i);
} while (i-- > 0);

Try the example on try.haxe.org.

References

“Do-while”, Haxe manual

Flow control

The flow or execution of a loop can be controlled by use of break and continue expressions.

Break

break exits the current loop. In case the loop is nested inside another loop, the parent loop is unaffected.

for (i in 0...10) {
    for (j in 0...10) {
        if (j == 5) break;
        trace(i, j);
    }
}

Try the example on try.haxe.org.

Continue

continue skips the current iteration of the loop at the point of the expression. In case the loop is nested inside another loop, the parent loop is unaffected.

for (i in 0...10) {
    for (j in 0...10) {
        if (j == 5) continue;
        trace(i, j);
    }
}

Try the example on try.haxe.org.