rustHow to join two Rust HashMaps?

Joining two Rust HashMaps can be done using the extend() method. This method takes ownership of the parameter and appends its key-value pairs to the original HashMap.

let mut map1 = HashMap::new();
map1.insert("a", 1);
map1.insert("b", 2);

let mut map2 = HashMap::new();
map2.insert("c", 3);
map2.insert("d", 4);

map1.extend(map2);

println!("{:?}", map1);

Output example

{"a": 1, "b": 2, "c": 3, "d": 4}

Code explanation

1. let mut map1 = HashMap::new(); - creates a new empty HashMap called map1
2. map1.insert("a", 1); - inserts a key-value pair into map1
3. map1.extend(map2); - takes ownership of map2 and appends its key-value pairs to map1
4. println!("{:?}", map1); - prints the contents of map1

Helpful links

• Rust HashMap Documentation

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