rustHow to get the length of a Rust HashMap?

The length of a Rust HashMap can be obtained using the len() method.

Example code

use std::collections::HashMap;

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

println!("Length of map: {}", map.len());

Output example

Length of map: 2

Code explanation

1. use std::collections::HashMap; - imports the HashMap type from the std::collections module.
2. let mut map = HashMap::new(); - creates a new empty HashMap instance.
3. map.insert("a", 1); - inserts a key-value pair into the HashMap.
4. map.insert("b", 2); - inserts another key-value pair into the HashMap.
5. println!("Length of map: {}", map.len()); - prints the length of the HashMap to the console.

Helpful links

• Rust HashMap Documentation

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