read4.md

HTML Links, JS Functions, and Intro to CSS Layout

HTMLLinks

links are created using the <a> tag the adding the location link inside it using the herf = "" attribute

links are used to link:

between	URL
website to another	absolute URL https://www.google.com/
page to another (same website)	relative URL about-us.html
part to part (same page)	#partId
open a new window	https://www.google.com target = "blank"
email links	mailto:[email protected]

JS Functions

A function is a list of statements (instructions) performs a specific task. It is a way to perform the same task in different parts in the code file without retyping the statements. It is a useful technique to make a fast executed programmed file because functions are not executed until they are called. In JavaScript there is a lot of saved functions can be used to modify the HTML content or make them interactive with the user as document.write();. functions are called by their names and filling their parameters with either values or variables contain values if function parameters are existed.Functions are made up by two methods:

method	script
function declaration	function calculate(length,width) {area = length*width; return area;}
expression function	var calculate = function(length,width) {area = length*width; return area;}

where are:

1. function is the function keyword
2. calculate is the function name
3. (length,width) are the function parameter could be more, less or null if function doesn’t need
4. area = length*width is a function statement to do a task, could be more than one
5. return area is the function returning value after the run and its optional depending on the function task

the previous function is called by calculate(x,y); where x and y are the function arguments, they are variables contain a number values assigned by the function user. Note the user can assign values directly as a function arguments calculate(5,10); but a best practice to assign variables.

Intro to CSS Layout

layout for HTML elemnts can be displayed in two ways:

• block level
• inline

for block level elements it starts in new lines while the inline elements can flow between surronding texts.

controlling the elements position can be done by:

1. normal flow
2. relative positioning
3. absolute positioning
4. fixed positioning
5. floating elements