JavaScript is an Object Oriented Programming (OOP) language.
JS是面向對象的編程語言（面向對象）。 （這里是基于對象還是面向對象大家可以搜索下）
An OOP language allows you to define your own objects and make your own variable types.
OOP語言可以讓你自定義對象和變量類型。

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Object Oriented Programming
被安置對象的編程
JavaScript is an Object Oriented Programming (OOP) language. An OOP language allows you to define your own objects and make your own variable types.
JS是(OOP)語言，這就可以讓你定義....(和上面的重復)
However, creating your own objects will be explained later, in the Advanced JavaScript section. We will start by looking at the built-in JavaScript objects, and how they are used. The next pages will explain each built-in JavaScript object in detail.
然而，我們將晚些在高級JS里介紹建立自定義對象。我們將開始觀察內建JS對象和如何使用它們。下頁將詳細介紹每個內建JS對象
Note that an object is just a special kind of data. An object has properties and methods.
注意，對象只是特殊類型的數據。對象有屬性和方法

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Properties
屬性
Properties are the values associated with an object.
屬性是對象的相連值
In the following example we are using the length property of the String object to return the number of characters in a string:
下面的例子我么使用了字符串對象的長度屬性來返回字符的數量：
<script type="text/javascript">
var txt="Hello World!"
document.write(txt.length)
</script>
The output of the code above will be:
上面的代碼就會輸出：
12

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Methods
方法
Methods are the actions that can be performed on objects.
對象的方法可以執行行為。
In the following example we are using the toUpperCase() method of the String object to display a text in uppercase letters:
下面的例子使用了字符串對象的toUpperCase()方法來顯示出文字的大寫：
<script type="text/javascript">
var str="Hello world!"
document.write(str.toUpperCase())
</script>
The output of the code above will be:
上面的代碼輸出：
HELLO WORLD!