1. JavaScript Functions and Arrays
Chapter 20
JavaScript
Functions and Arrays

2. JavaScript Functions
Algorithm is a finite set of instructions that are general, consistent, finite, precise and take input and produce output
Function is defined as a set of statements that takes input, use an algorithm, and produce output

3. JavaScript Functions function functionName ([param1, param2…]){
function statements goes here
return output // optional
alert(“hello”); // non-reached statement
} // end of function
// function call
returnValue = functionName([param1, param2…]);
* See example 20.1 ~ 20.4

4. JavaScript Array
Array is an ordered set of values associated with a single variable name
Array is a JavaScript predefined Object and “new” command to define it
First element in array is 0
Defined array
myArray = new Array(4);
myArray = new Array (“red”,”green”,”blue”);

5. JavaScript Array Array object property – length Array object method
arrLength = myArray.length
Array object method
Reverse()
Sort()
Concat()
Slice()
Push() = add one element to the end of array
Pop() = remove one element from the end of array
See example 20.7

6. JavaScript Array Array Access – for … in statement var x
var mycars = new Array()
mycars[0] = "Saab"
mycars[1] = "Volvo"
mycars[2] = "BMW"
for (x in mycars){
document.write(mycars[x] + "<br />") }
See Example 20.7

7. JavaScript Array Multi-dimensional Array
Two dimension array 2 rows 3 columns
arr = new Array(new Array(2), new Array(3));
arr = new Array(new Array(3,9,2), new Array(5,1,7));
See example 20.6