HTML

table

• A table represents information in a grid format.
• Grids allow us to understand complex data by referencing information on two axes.
• Each block in the grid is referred to as a table cell
• The <table> element is used to create a table. The contents of the table are written out row by row.
  • start of each row It is followed by one or more elements (one for each cell in that row).(The td stands fortable data.)
  • At the end of each cell you use a closing </td> tag.
  • The <th> element is used just like the <td> element but its purpose is to represent the heading for either a column or a row. (The th stands for table heading.)
• The colspan attribute can be used on a <th> or <td> element and indicates how many columns that cell should run across.
• The rowspan attribute can be used on a <th> or <td> element to indicate how many rows a cell should span down the table.
• The headings of the table should sit inside the element.
• The body should sit inside the element.
• The footer belongs inside the element.
• Some of the HTML editors that come in content management systems offer tools to help draw tables. If the first row of your table only contains <th> elements then you may find that the editor inserts a <thead> element automatically.

Java Script

Object

constructor

• the new keyword and the object constructor create a blanck object then you can add properties and methods to object var object_name = new object()
• then using dot notation you can add properties and methods object_name.property_name = value; object_name.method_name = function(){};
• to delete property delete object_name.property_name;
• Sometimes you will want several objects to represent similar things. Object constructors can use a function as a template for creating objects
• this keyword is used instead of the object name to indicate that the property or method belongs to the object that this function creates.
  • commonly used inside functions and objects.
• The name of a constructor function usually begins with a capital letter
• A FUNCTION IN GLOBAL SCOPE :When a function is created at the top level of a script
• method When a function is defined inside an object To access the properties or methods of the object,use dot notation: object_name.property_name;
• MULTIPLE OBJECTS :When you need to create multiple objects within the same page, you should use an object constructor to provide a template for the objects.
• array is a special type of object the key for each value is index
  • array can contain an multi object and object can contain multi array
• Browsers come with a set of built-in objects that represent things like the browser window and the current web page shown in that window.
• **object model ** is a group of objects, each of which represent related things from the real world three groups of built in object model :
  • The Browser Object Model: contains objects that represent the current browser window or tab. It contains objects that model things like browser history and the device’s screen.
  • DOCUMENT OBJECT MODEL:uses objects to create a representation of the current page. It creates a new object for each element
  • GLOBAL JAVASCRIPT OBJECTS: represent things that the JavaScript language needs to create a model of.