# API Reference

## Array

### .filter(callback) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter))

Executes a `function` on every element of the Array. It returns a new Array that contains only the elements for which the provided `function` returned `true`.

Example:

```
var myArray = [5, 6, 1, 2, 10];

var filteredArray = myArray.filter(function(num) {
    return num > 3; // Returns true only if the number is greater than 3
});

// filteredArray is [5, 6, 10]
```

### .forEach(callback) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach))

Allows to execute a `function` on each and every element of the Array.

Example:

```
var myArray = ['Mickey', 'Goofy', 'Donald'];

myArray.forEach(function(name) {
   console.log('Hello' + name);
};

// Console Output
Hello Mickey
Hello Goofy
Hello Donald
```

### .push(element) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push))

Appends an element at the end of the Array.

Example:

```
var myArray = [20, 100, 30];

myArray.push(50);

// myArray is now [20, 100, 30, 50]
```

## Event

### .target ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/API/Event/target))

Returns the element on which the event was captured.

### .preventDefault() ([see in MDN](https://developer.mozilla.org/en/docs/Web/API/Event/preventDefault))

Cancels the default event behavior.

## String

### .replace(pattern, replacement) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace))

Returns a copy of the String with the given *pattern* replaced with another String.

Example:

```
var myString = 'This and that';

var newString = myString.replace('and', 'or');

// newString is 'This or that'
```

### .trim() ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trim))

Returns the original String without the whitespaces that it might have at the beginning or at the end.

Example:

```
var myString = '    Chocolate  ';

var newString = myString.trim();

// newString is 'Chocolate'
```

## JSON

### .parse(jsonString) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse))

Converts a JSON string into a Javascript Object.

```
var myObject = JSON.parse('{"type": "door", "state": "open"}');

// myObject is { type: 'door', state: 'open' }
```

### .stringify(object) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify))

Converts a Javascript Object into a JSON string.

```
var myObject = { type: 'door', state: 'open' };
var jsonString = JSON.stringify(myObject);

// jsonString is '{"type":"door","state":"open"}'
```

## document

### .querySelector(cssSelector) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelector))

Returns the first element that matches the provided CSS selector.

Example:

```
// HTML
<div class="container">
   <div id="myElement">
      <span>Hello!</span>
   </div>
</div>

// Javascript
var myElement = document.querySelector('#myElement');

// myElement contains a reference to <div id="myElement"></div>
```

## Element

### .innerHTML ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/API/Element/innerHTML))

Returns the HTML contained inside an Element. It can be set to a new value.

Example:

```
// HTML
<div id="myElement">
  <span>Hello!</span>
</div>

// Javascript
var myElement = document.querySelector('#myElement');

// myElement.innerHTML returns '<span>Hello!</span>'

myElement.innerHTML = '<div>Something else</div>';

// Now the HTML is this:
<div id="myElement">
  <div>Something else</div>
</div>
```

### .previousElementSibling ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/API/NonDocumentTypeChildNode/previousElementSibling))

Returns the Element before the selected one.

Example:

```
// HTML
<div class="container">
   <span>One</span>
   <span class="selected">Two</span>
   <span>Three</span>
</div>

// Javascript
var selected = document.querySelector('.selected');
var previous = selected.previousElementSibling;

// previous is <span>One</span>
```

### .dataset ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/dataset))

Returns the map of the `data-` attributes of the selected element.

Example:

```
// HTML
<div id="myElement" data-type="door" data-state="open"></div>

// Javascript
var door = document.querySelector('#myElement');
var dataSet = door.dataset;

// dataSet is { type: 'door', state: 'open' }
```

### .value ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input))

Returns or sets the value of the input field.

## console

### .log(text) ([see in MDN](https://developer.mozilla.org/en-US/docs/Web/API/Console/log))

Writes a message in the browser's console.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://bootcamp.shetechitaly.org/api-reference.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.