rustHow to count elements in a Rust HashMap?

To count elements in a Rust HashMap, you can use the len() method. This method returns the number of elements in the HashMap.

Example code

use std::collections::HashMap;

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

println!("Number of elements in the map: {}", map.len());

Output example

Number of elements in the map: 2

Code explanation

1. use std::collections::HashMap;: This line imports the HashMap type from the std::collections module.

2. let mut map = HashMap::new();: This line creates a new empty HashMap and stores it in the map variable.

3. map.insert("a", 1); and map.insert("b", 2);: These lines insert two key-value pairs into the map HashMap.

4. println!("Number of elements in the map: {}", map.len());: This line prints the number of elements in the map HashMap.

Helpful links

• Rust HashMap Documentation

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