Pemrograman Dasar

1. PemrogramanDasar Basic Elements Of Java

2. Compiling and Runninga Java Application

3. Portable Java App

4. Java Platform • Platform: hardware or software environment in which a program runs. • Oracle has two products that implement Java Platform Standard Edition (Java SE) 7: • Java SE Development Kit (JDK) 7 • Java SE Runtime Environment (JRE) 7.

5. Java Platform SE 7

6. Typical Java Development Environment

7. Basic Lexical Elements • Character set • 16-bit Unicode • Legal characters • Keywords • Reserved words, special meaning, illegal for identifiers • Identifiers • Names of declared entities, e.g. variables, constants • Variables • A variable is a storage location, something that can hold a value to which a value can be assigned • Literals • Constants or values, e.g. 12, 17.9, “Hello”

8. Basic Lexical Elements • Other notations • Operators, e.g. +, -, *, /, etc. • Block symbols, e.g. pair of {} • Comments • Help developers, ignored by compiler • e.g. /* Program 1 */ // Function to count Circle area

9. Character Set • Java programs are written using Unicode character set (16 bit), which include: • Capital letters: A .. Z • Small letters: a .. z • Numbers: 0 .. 9 • Punctuation marks, e.g. ‘!’ , ‘,’,’?’, etc. • Other characters or symbols, e.g. • Arithmetic symbols, e.g. ‘+’, ‘-’, ‘/’, etc. • from many natural languages Pengantar Bahasa C - TIF UB 2010

10. Keywords • Keywords cannot be used as identifiers (reserved) because they have special meaning within the language. Pengantar Bahasa C - TIF UB 2010

11. Identifiers • Used for names of declared entities such as variables, constants, and labels • Must start with a letter, followed by letters, digits, or both. • Identifiers are case-sensitive • The terms letter and digit are broad in Unicode: if something is considered a letter or digit in a human language, you can probably use it in identifiers. • "Letters" can come from Chinese, Korean, Gurmukhi, Georgian, Devanagari, and almost any other script written in the world today. Pengantar Bahasa C - TIF UB 2010

12. Identifiers • Letters also include any currency symbol (such as $, ¥, and £) and connecting punctuation (such as _). • Identifiers can be as long as you like, but use some taste. • Identifiers that are too long are hard to use correctly and actually obscure your code. • Cannot use keywords (e.g. for, if, while, etc) • Valid identifiers, e.g.: • name, x1, _total, cubic • Invalid identifiers, e.g.: • 1kali, int Pengantar Bahasa C - TIF UB 2010

13. (Data) Types • Every expression has a type that determines what values the expression can produce. • The type of an expression is determined by the types of values and variables used within that expression. • Types are divided into the primitive types and the reference types.

14. Primitive Data Types

15. Literals • Also known as “values” or “constants” • Each (data) type has literals, which are the way that constant values of that type are written. • Boolean literals • Character literals • Integer literals • Floating-point literals • String literals • Reference literals • Class literals

16. Literals • Boolean literals • Only true and false • Character literals • Appear with single quotes, e.g. ‘Z’, ‘a’, ‘2’, ‘\u004e’ • Certain special characters can be represented by an escape sequence, e.g.:

17. Literals • Integer literals • Integer constants are a sequence of octal, decimal, or hexadecimal digits. • The start of a constant declares the number's base: A 0 (zero) starts an octal number (base 8); a 0x or 0X starts a hexadecimal number (base 16); and any other digit starts a decimal number (base 10). • E.g. all the following numbers have the same value 29 035 0x1D 0X1d

18. Literals • Floating-point literals • Expressed in either decimal or hexadecimal • The decimal form consists of a string of decimal digits with an optional decimal point, optionally followed by an exponent the letter e or E, followed by an optionally signed integer. • e.g. all these literals denote the same floating-point number: 18. 1.8e1 .18E+2 180.0e-1

19. Literals • Floating-point literals (continued) • The hexadecimal form consists of 0x (or 0X), a string of hexadecimal digits with an optional hexadecimal point, followed by a mandatory binary exponent the letter p or P, followed by an optionally signed integer. • The binary exponent represents scaling by two raised to a power. • e.g. all these literals denote the same floating-point number (decimal 18.0): 0x12p0 0x1.2p4 0x.12P+8 0x120p-4

20. Literals • Floating-point literals (continued) • Floating-point constants are of type double unless they are specified with a trailing f or F, which makes them float constants, such as 18.0f. • A trailing d or D specifies a double constant. • There are two zeros: positive (0.0) and negative (-0.0). • Positive and negative zero are considered equal when you use == but produce different results when used in some calculations.

21. Literals • String literals (continued) • String literals appear with double quotes, e.g. “Welcome”, “salam”, "\u0633\u0644\u0672\u0645". • Any character can be included in string literals, with the exception of newline and " (double quote). • Newlines are not allowed in the middle of strings. • If you want to embed a newline character in the string, use the escape sequence \n. • To embed a double quote use the escape sequence \". • A string literal references an object of type String.

22. Variables • A variable is a storage location, something that can hold a value to which a value can be assigned. • A variable declaration states the identifier (name), type, and other attributes of a variable. • e.g. float x, y; // is the same as float x; float y; float x = 3.14f, y = 2.81f; // is the same as float x = 3.14f, y = 2.81f; // is the same as float x = 3.14f; float y = 2.81f;

23. Variables • Instance variables (non-static fields) • Class variables (static fields) • Local variables • Parameters

24. Variables public class Bicycle { int cadence = 0; // instance variable static int wheels = 2; // static variable … // formal parameter: decrement void applyBrakes(int decrement) { speed = speed - decrement; } // local variable: states void printStates() { String states = "cadence: "+cadence+ ",speed: "+speed+", gear: "+gear; System.out.println(states); } }