rustHow to get a reference to a key in a Rust HashMap?

You can get a reference to a key in a Rust HashMap using the get method. This method returns an Option<&V> where V is the type of the value associated with the key.

Example

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("key1", "value1");
map.insert("key2", "value2");

let value = map.get("key1");
println!("{:?}", value);

Output example

Some("value1")

The get method takes a reference to the key and returns an Option type. If the key is present in the HashMap, the Option will contain a reference to the value associated with the key. If the key is not present, the Option will be None.

Code explanation

• get method: takes a reference to the key and returns an Option type
• Option type: if the key is present, contains a reference to the value associated with the key; if the key is not present, is None

Helpful links

• Rust HashMap documentation

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