rustHow to merge hashmaps in Rust

Merging two hashmaps in Rust can be done using the .extend() method. This method takes an iterator of key-value pairs and adds them to the hashmap.

Code example:

let mut map1 = hashmap!{
    "a" => 1,
    "b" => 2,
};

let mut map2 = hashmap!{
    "c" => 3,
    "d" => 4,
};

map1.extend(map2);

Output

map1 will now contain the key-value pairs from both map1 and map2: {"a": 1, "b": 2, "c": 3, "d": 4}

Explanation:

• let mut map1 = hashmap!{...}: creates a mutable hashmap map1 with the given key-value pairs
• let mut map2 = hashmap!{...}: creates a mutable hashmap map2 with the given key-value pairs
• map1.extend(map2): adds the key-value pairs from map2 to map1

Helpful links:

• Rust Documentation - HashMap
• Rust Documentation - extend()

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