// for-in loop demo
print("=== array ===")
let arr = [10, 20, 30]
for (x in arr) {
    print(x)
}

print("=== object keys ===")
let obj = {name: "Aster", year: 2025}
let keys = ""
for (k in obj) {
    keys = keys + k + " "
}
print(keys)

print("=== string chars ===")
for (c in "Hi") {
    print(c)
}

print("=== break ===")
for (x in [1, 2, 3, 4, 5]) {
    if (x == 3) { break }
    print(x)
}