# Overview

The **`size` function** in `HashMap` is used to find the size of a `HashMap`. The size entails all of the key-value pairs in a `HashMap`. As `HashMap` is defined in the `util` package in Java, you must first import the `util` package before using the `size` function, as shown below:

```Java
import java.util.*;
``` 

The syntax for `size` is shown below:

```Java
hashmapName.size()
```

# Parameters

The `size` function takes no mandatory parameters as input.

# Return value

The `size` function returns the number of keys in a `Hashmap`.

# Example

The example below will help you understand the `size` function better. First, we define the `HashMap` and add keys to it, using the `put` function. Then, we print out the size of the `HashMap` using the `size` function.

import java.util.*;

class HelloWorld {
    public static void main( String args[] ) {
        
        HashMap<String, Integer> hash = new HashMap<String, Integer>();

        hash.put("Samia", 22);
        hash.put("Sana", 21);

        System.out.println("Size of Map: " + hash.size());
    }
}

What is size in Java HashMap?

The size function in HashMap returns the number of key-value pairs, requiring no parameters.