Maps: Making a map

● Beginner2 min

Write key: value pairs in square brackets, or start empty with [:] and a type.

fn main() {
    let empty: [String: Int] = [:]
    const full = ["asha": 31, "omar": 27]
    print(empty.len())
    print(full.len())
}

kavach run create.kav

When you know a map will get many entries, Map.with_capacity(n) makes room for them up front, so filling it never stops to grow:

fn main() {
    let ages: [String: Int] = Map.with_capacity(3)
    ages["asha"] = 31
    ages["ravi"] = 27
    ages["mira"] = 9
    ages["omar"] = 40
    print(ages.len())
    print(ages)
}

kavach run room.kav

4["asha": 31, "ravi": 27, "mira": 9, "omar": 40]