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Flow control

For in

let iterable = ["a", "b", "c", "d", "e", "f", "g", "h"];
for value in iterable {
if value == "g" {
// stopping at g
break;
}
if value == "b" {
// skipping b
continue;
}
log(value);
}
/**
* prints
a
c
d
e
f
**/

For through a range

// print numbers from 0 to 9
for value in 0..10 {
log("{value}");
}

// prints numbers in reverse order from 10 to 0
for value in 10..-1 {
log("{value}");
}

// include end
for value in 1..=5 {
log("{value}");
}

If elif else

let grade = (score: num): str => {
// Parentheses are optional in conditions.
// However, curly braces are required in `if/else` statements.
if 0 < score && score < 55 {
return "F";
} elif 55 <= score && score < 65 {
return "C";
} elif 65 <= score && score < 75 {
return "B";
} elif 75 <= score && score <= 100 {
return "A";
} else {
return "Invalid grade";
}
};

log("54 is {grade(54)}"); // 54 is F
log("62 is {grade(62)}"); // 62 is C
log("68 is {grade(68)}"); // 68 is B
log("99 is {grade(99)}"); // 99 is A
log("101 is {grade(101)}"); // 101 is Invalid grade

While

let var i = 0;
while i < 100 {
i = i + 1;
if i == 20 {
// although the while loop goes to 100, we break it at 20
break;
}
if i % 2 == 0 {
// continue for even numbers
continue;
}
log("{i}");
}
/**
* prints
1
3
5
7
9
11
13
15
17
19
**/