for (;;)
    ;
for (;;)
    1
for (1;;)
    1
for (; 1;)
    1
for (;; 1)
    1

for (;;) {}
for (1;;) {}
for (; 1;) {}
for (;; 1) {}

for (;;) {
    1
}
for (1;;) {
    1
}
for (; 1;) {
    1
}
for (;; 1) {
    1
}

for (;;)
    ;
for (;;)
    ;
for (;;) {}
for (;;) {}

for (;;) {
    1
}
1
x
// for

for (1; 2; 3)
    1;
for (1; 2; 3) {
    1
}
;

for ((1);(2);(3))
    1
for ((1);(2);(3)) {
    1
}

for ((1);(2);(3))
    1
for ((1);(2);(3)) {
    1
}

for (1; 2; 3)
    1
for (1; 2; 3) {
    1
}

for (var x = 1; x < 10; ++x)
    1;
for (var x = 1; x < len; ++x)
    1;
for (var x = 1, len = 10; x < len; ++x)
    1;
for (var x = 1, len = 10; len = 20, x < len; ++x)
    1;
for (var x = 1, len = 10; len = 20, x < len; len = 15, ++x)
    1;

for (x = 1; x < 10; ++x) {
    1
}
for (x = 1; x < len; ++x) {
    1
}
for (x = 1, len = 10; x < len; ++x) {
    1
}
for (x = 1, len = 10; len = 20, x < len; ++x) {
    1
}
for (x = 1, len = 10; len = 20, x < len; len = 15, ++x) {
    1
}

for (var x = 1; x < 10; ++x) {
    1
}
for (var x = 1; x < len; ++x) {
    1
}
for (var x = 1, len = 10; x < len; ++x) {
    1
}
for (var x = 1, len = 10; len = 20, x < len; len = 15, ++x) {
    1
}

for (var x = 1; x < 10; ++x) {
    1
}
for (var x = 1; x < len; ++x) {
    1
}
for (var x = 1, len = 10; x < len; ++x) {
    1
}
for (var x = 1, len = 10; len = 20, x < len; len = 15, ++x) {
    1
}

for (1; 2; 3)
    for (4; 5; 6)
        for (7; 8; 9)
            ;
for (1; 2; 3) {
    if (true) {
        for (4; 5; 6)
            0
    }
    for (7; 8; 9)
        ;
}

for (var x, y, z; !x && y; ++x, ++y) {}
for (var x = [], y = [1, 2, 3]; true; false) {}

// for..in

for (x in obj)
    ;
for (x in (obj))
    ;
for (var x in window)
    ;
for (var x in (window))
    ;
for (var {foo} in window)
    ;
for (var [x, y] in [1, 2, 3])
    ;

// for..of

for (x of [1, 2, 3])
    ;
for (x of ([1, 2, 3]))
    ;
for (var x of window)
    ;
for (var x of (window))
    ;
for (var {foo} of window)
    ;
for (var [x, y] of [1, 2, 3])
    ;

// ES2018 - Async Iteration / Async Generators

async function f() {
    for await (x of [])
        ;
    for await (x of [1, 2, 3])
        ;
    for await (x of ([1, 2, 3]))
        ;
    for await (var x of window)
        ;
    for await (var x of (window))
        ;
    for await (let {foo} of window)
        ;
    for await (let [x, y] of [1, 2, 3])
        ;
}