Why do we need a coding standard?

What is good about it and how is it useful?

Should begin with a letter and may contain additional letters and digits. Identifiers are the same as variables.

• Use descriptive names for all variables, function names, constants and other identifiers. Use single letters only for the counter in loops.
• Variable names start with lower-case
• Multi-word identifiers are internally capitalized
• Do not use hyphens or underscores to separate multi-word identifiers.

What about the unicode set?

This is the format: \uHHHH

Remember any other escape characters such as \n, \t and \\?

The first letter of each word is capitalized, examples:

Mammal,  SeaMammal

The first letter of each, except the first, word is capitalized, examples:

getAge, setHeight

The first letter of each, except the first, word is capitalized, examples:

age, brainSize

Every letter is capitalized and underscores are used between words, examples:

MAX_HEIGHT, MAX_AGE

As you may have noticed, many of Java's keywords are borrowed from C/C++. Also, as in C/C++, keywords are always written in lowercase. Generally speaking, Java's keywords can be categorized according to their function as follows (examples are in parenthesis):

Data declaration keywords (boolean, float, int)

Loop keywords (continue, while, for)

Conditional keywords (if, else, switch)

Exception keywords (try, throw, catch)

Structure keywords (class, extends)

Modifier and access keywords (private, public)

Miscellaneous keywords (true, null)

The following keywords and their use, you SHOULD know.

Where is it appropriate to declare a variable? Does it make a difference?

• Why object oriented programming?
• Objects need to be built, so we need constructors.
• Instance variables and the role they play when defining objects.
• What about methods of an object?

int[] array = new int[5]; // one-dimensional array

it may also be declared as:

int[] array = {1, 2, 3, 4, 5}; // it is initialized and declared at the same time.

Arrays can be of any primitive data type or object. Arrays have an instance variable "length" that we can access to find out how big the array is. Remember that an Array can throw an IndexOutOfBoundsException. Make use of it to make your code safe.

Must import java.util.*;

Unlike arrays, vectors can only hold objects, no primitive data types are allowed. Vectors can grow big and unbounded. You may want to specify the capacity of the vector but you don’t need to. The default capacity is 10 and it doubles in size every time the capacity is reached.

Just like arrays have the "length" instance variable, Vectors have a .size() method that returns the current size of the vector.

• void .addElement(Object obj)
• void .setElementAt(Object obj, int index)
• Object .elementAt(int index)
• void .insertElementAt(Object obj, int index)
• void .removeElementAt(Object obj, int index)

Vector v = new Vector();

Enumeration e = v.elements();

While(e.hasMoreElements()){

Object o = e.nextElement;

// we do something with each element.

}

Pages 436, 437 AND 438

You need to know:

• Arithmetic operators in table A7.
• Incrementing and decrementing operators int Table A.8.
• Good to know but not necessary the Assignment operators in table A.9
• Relational operators in table A.10
• Logical operators in table A.11

Must be familiar with:

• for loops
• while loops
• if statements
• switch – case statements

• Creating customized classes and methods.
• JAVA Applets
• JAVA Stand-alone applications
• Compiling and running JAVA programs