> For the complete documentation index, see [llms.txt](https://hemantajax-2.gitbook.io/es6-step-by-step/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hemantajax-2.gitbook.io/es6-step-by-step/default-parameters.md).

# Default Parameters

```javascript
function greet(greeting, name="Anonymous"){
    console.log(greeting +", "+ name);
}

greet(); // undefined, Anonymous
greet('Hello'); // Hello, Anonymous
greet('Hello', 'Dady'); // Hello, Dady
```

```javascript
// ES5
function greet(cb){
    cb();
}

greet(function(){
    console.log("completed"); // completed
})

// ES6
function greet(() => console.log("completed")){
    cb();
}
greet();
```