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JavaScript Terminology.

• JavaScript programming uses specialized terminology.
• Understanding JavaScript terms is fundamental to understanding the script.
• Objects, Properties, Methods, Events, Functions, Values, Variables, Expressions, Operators.

Objects

• Objects refers to windows, documents, images, tables, forms, buttons or links, etc.
• Objects should be named.
• Objects have properties that act as modifiers.

Properties

• Properties are object attributes.
• Object properties are defined by using the object's name, a period, and the property name.
• e.g., background color is expressed by: document.bgcolor .
• document is the object.
• bgcolor is the property.

Methods

• Methods are actions applied to particular objects. Methods are what objects can do.
• e.g., document.write(”Hello World")
• document is the object.
• write is the method.

Events

• Events associate an object with an action.
• e.g., the OnMouseover event handler action can change an image.
• e.g., the onSubmit event handler sends a form.
• User actions trigger events.

Functions

• Functions are named statements that performs tasks.
• e.g., function doWhatever () {statement here}
• The curly braces contain the statements of the function.
• JavaScript has built-in functions, and you can write your own.

Values

• Values are bits of information.
• Values types and some examples include:
• Number: 1, 2, 3, etc.
• String: characters enclosed in quotes.
• Boolean: true or false.
• Object: image, form
• Function: validate, doWhatever

Variables

• Variables contain values and use the equal sign to specify their value.
• Variables are created by declaration using the var command with or without an initial value state.
• e.g. var month;
• e.g. var month = April;

Expressions

• Expressions are commands that assign values to variables.
• Expressions always use an assignment operator, such as the equals sign.
• e.g., var month = May; is an expression.
• Expressions end with a semicolon.

Operators

• Operators are used to handle variables.
• Types of operators with examples:
• Arithmetic operators, such as plus.
• Comparisons operators, such as equals.
• Logical operators, such as and.
• Control operators, such as if.
• Assignment and String operators.