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Rust program to check the given HashMap is empty or not

Rust | HashMap Example: Write a program to check whether the given HashMap is empty or not.
Last Updated : October 17, 2021

Problem Statement

In this program, we will create two HashMaps and then we will check created maps are empty or not using the is_empty() method.

Program/Source Code

The source code to check given HashMap is empty or not is given below. The given program is compiled and executed successfully.

// Rust program to check the given 
// HashMap is empty or not

use std::collections::HashMap;

fn main() 
{
    let mut map1 = HashMap::new();
    let mut map2: HashMap<&str, i32> = [].iter().cloned().collect();
    
    map1.insert("Key1", 101);
    map1.insert("Key2", 102);
    map1.insert("Key3", 103);
    map1.insert("Key4", 104);

    if map1.is_empty()
    {
        println!("The map1 is an empty HashMap");
    }
    else
    {
        println!("The map1 is not an empty HashMap");
    }
    
    if map2.is_empty()
    {
        println!("The map2 is an empty HashMap");
    }
    else
    {
        println!("The map2 is not an empty HashMap");
    }
}

Output

The map1 is not an empty HashMap
The map2 is an empty HashMap

Explanation

Here, we created two HashMaps. Then we checked created HashMaps are empty or not using the is_empty() method and printed the appropriate message.

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