Dom

Every web page is a document object.

Tags/elements are referred to as nodes, they all have an ID name. A block of text can also be considered a node.

Date Objects

Do you ever shut up!

<script>
       function saySomething() {
document.write("Blah ");
       }
       setInterval("saySomething()",              500);//1000 mm = 1 sec


        function printTime() {
var now = new Date();// Date is a pre-built object
//This gets the current date/time and stores it in the now variable
var month = now.getMonth();//method to get hour from date object
var day = now.getDate();
var year = now.getFullYear();

var hour = now.getHours();//method to get hour from date object
var minute = now.getMinutes();
var sec = now.getSeconds();
document.write(month + "/" + day + "/" + year + "--" + hour + ":" + minute + ":" + sec + "<br>");
}

setInterval("printTime()", 1000);
</script>

Math

Some Properties of the Math Object

<script>
document.write("Euler's constant - " + Math.E + "<br>Mmmm Pi - " + Math.PI + "<br>"); 
</script>

"Hey there you little sqrt."

<script>
var n = prompt("Enter a Number", "");
var answer = Math.sqrt(n);
alert("The square root of " + n + " is " + answer);
</script>

Dynamic Loop Condition

<script>
var favoriteAnimals = new Array("Brown Chicken", "Brown cow", "Green Tortoise", "White Rabbit", "Pink Panther");
favoriteAnimals.sort();

for (i = 0; i < favoriteAnimals.length; i ++) {
document.write(favoriteAnimals[i] + "<br>");
}

</script>

Now if the number of the items in the favoriteAnimals Array changes  so will the conditional of the forloop.

User Defined Variables

♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦

You have such 

a beautiful 

Movie Star Name

<script>
var middleName = prompt("Movie Star Name:", "What is your middle name");
var streetName = prompt("Movie Star Name:", "What street do you live on");
//you probably want a vacant text-field, in which case you can use an empty set of quotes
document.write("Your movie star name is " + middleName + " " + streetName + "!");
</script>
♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦

Use the Array index as the counter to let 

the user add items to the Array

<script>
var userDefinedArray = new Array(10);
for (i = 1; i <= 10; i++) {
userDefinedArray[i] = prompt("What is your number " + i + " favorite animal", "");
}
document.write("Your ten most favorite animals are" + userDefinedArray.join(", "));
</script>

Array Methods

Concatenate Arrays

                                                                             
<script>
var design = new Array("Typograhpy", "Photoshop", "Illustator");
var development = new Array("HTML5", "CSS3", "PHP", "MySQL", "JavaScript");
var programming = new Array(".NET", "MS SQL", "Java");

var courses = design.concat(development, programming);


document.write(courses[10]);

</script>

Join and Pop

<script>
var design = new Array("Typograhpy",           "Photoshop", "Illustator");
var development = new Array("HTML5", "CSS3", "PHP", "MySQL", "JavaScript");
var programming = new Array(".NET", "MS SQL", "Java", "undefined");
        //3 arrays
programming.pop();//This will remove the last index from the 3rd Array 
document.write(programming[4] + "<br>");//I am undefined
//Now add both the 2nd and 3rd Arrays to the 1st Array and store in a new Array
var courses = design.concat(development, programming);

//////////////////////////////////////////////////////////////////////////////////////////////////////
var join1 = courses.join(", ");//join, and add comma - space between indices
document.write(join1 + "<br>");
        //////////////////////////////////////////////////////////////////////////////////////////////////////

</script>

Instead of writing these last two lines, you can simply write:
         //////////////////////////////////////////////////////////
         document.write(courses.join(", "));
         //////////////////////////////////////////////////////////

This next method should be called shove, because it shoves new elements into your Array:
        courses.push("Flash", "jQuery");

List alphabetically:
     courses.sort();

Reverse it first, then join echo:
        courses.reverse();

document.write(courses.join(", "));

Arrays

<script>

var beatles = new Array("johny", "george", "ringo", "paul", "paul2");

document.write(beatles[3] + " is dead");//access the array index

</script>

##############################################################

<script>

var beatles = new Array(3);

beatles[0] = "john";

beatles[1] = "george";

beatles[2] = "ringo";

beatles[3] = "paul";

beatles[4] = "paul2";

document.write(beatles[3] + " is dead");

</script>

//You can't always enter all your information into your array as soon as you create it, and you might not know how many items the array will include,

<script>

var myClasses = new Array();

 myClasses[0] = "Web 110: A+";

myClasses[1] = "Web 120: A+";

myClasses[2] = "ITC 280: A+";

myClasses[3] = "Web 150: A+";

myClasses[4] = "Math 85: F-";

myClasses[5] = "Phil 106: A-";

//Arrays are objects and have Properties and Methods.

 document.write(myClasses.length);

</script>

An Associative Array uses strings instead of numbers as an index

<script>
var weather = new Array();
weather["seattle"] = "party cloudy";
weather["portland"] = "chance of rain";
weather["los angeles"] = "Who Cares";

document.write("The weather will be " + weather["portland"] + " today in Portland.");
</script>

Whatever