This JavaScript code defines a function called `isEven` that takes one argument, `num`. It checks if the number is even by using the modulo operator (`%`). The code then calls the `isEven` function with the argument 4, printing `true` to the console.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:
Explain this JavaScript function.

### Input:
`javascript
function isEven(num) {
    return num % 2 === 0;
}
console.log(isEven(4));
`

### Response:
This JavaScript code defines a function called `isEven` that takes one argument, `num`. It checks if the number is even by using the modulo operator (`%`). The code then calls the `isEven` function with the argument 4, printing `true` to the console.<|im_end|>