rustHow to get all keys from a Rust HashMap?

You can get all keys from a Rust HashMap using the keys() method. This method returns an iterator over the keys of the map.

Example code

use std::collections::HashMap;

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

for key in map.keys() {
    println!("{}", key);
}

Output example

a
b

Code explanation

• use std::collections::HashMap: imports the HashMap type from the std::collections module.
• let mut map = HashMap::new(): creates a new empty HashMap and stores it in the map variable.
• map.insert("a", 1): inserts a key-value pair into the map variable.
• map.keys(): returns an iterator over the keys of the map variable.
• for key in map.keys(): iterates over the keys of the map variable.
• println!("{}", key): prints the current key to the console.

Helpful links

• Rust HashMap documentation

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