1. IntroductionIntroduction  Computer program: an ordered sequence of statements whose objective is to accomplish a task.  Programming: process of planning and creating a program  Programming Language: a set of symbols, special words, and rules for using those symbols and special words to create statements to implement the ordered sequence of instructions to accomplish a task  Computer program: an ordered sequence of statements whose objective is to accomplish a task.  Programming: process of planning and creating a program  Programming Language: a set of symbols, special words, and rules for using those symbols and special words to create statements to implement the ordered sequence of instructions to accomplish a task

2. The Basics of a Java Program  Java program: collection of classes  There is a main method in every Java application program  Token: smallest individual unit of a program  Word symbols or reserved words  Identifiers or names for things in the program  Special symbols (operators …)  Java program: collection of classes  There is a main method in every Java application program  Token: smallest individual unit of a program  Word symbols or reserved words  Identifiers or names for things in the program  Special symbols (operators …)

3. Reserved words in Java  A reserved word is a part of the computer language we are using. In is a special word that gives the compiler a specific instruction it can understand  Abstract, boolean, break, byte, case, catch, char, class,  const, continue, default, do, double, else, extends,  false, final, finally, float, for, goto, if, import, int,  implements, instanceof, interface, long, native, new,  null, package, private, protected, public, return, short,  static, strictfp, super, switch, synchronize, this, throw,  throws, translate, true, try, void, volatile, while  A reserved word is a part of the computer language we are using. In is a special word that gives the compiler a specific instruction it can understand  Abstract, boolean, break, byte, case, catch, char, class,  const, continue, default, do, double, else, extends,  false, final, finally, float, for, goto, if, import, int,  implements, instanceof, interface, long, native, new,  null, package, private, protected, public, return, short,  static, strictfp, super, switch, synchronize, this, throw,  throws, translate, true, try, void, volatile, while

4. Java Identifiers I  Names of things  Must contain only:  Letters (upper and lower case)  Digits (0-9)  The underscore character (_)  The dollar sign ($)  Names of things  Must contain only:  Letters (upper and lower case)  Digits (0-9)  The underscore character (_)  The dollar sign ($)

5. Java Identifiers II  Must not begin with a number  Cannot be a reserved word  Identifiers beginning with an underscore are used for specific purposes and should be avoided in general use  Java is case sensitive. The identifier Toy is not the same as the identifier toy  Must not begin with a number  Cannot be a reserved word  Identifiers beginning with an underscore are used for specific purposes and should be avoided in general use  Java is case sensitive. The identifier Toy is not the same as the identifier toy

6. Illegal Identifiers

7. Which Are Legal Java Identifiers?  cycle  A!star  int  Score  Y-Z  Trial#2  This_One$  while_$__zero  cycle  A!star  int  Score  Y-Z  Trial#2  This_One$  while_$__zero  $MyProgram  FOR  3constant_values  “MaxScores”  unsigned  _External_Prog  Mary’s  StarChart

8. Binary Arithmetic Operators in Java  A Binary Operator operates on two arguments  + addition  -subtraction  * multiplication  / division  % modulus or remainder  A Binary Operator operates on two arguments  + addition  -subtraction  * multiplication  / division  % modulus or remainder

9. Unary Arithmetic Operators in Java  A Unary Operator operates on one argument  + addition  -subtraction  ++ increment  --decrement  A Unary Operator operates on one argument  + addition  -subtraction  ++ increment  --decrement

10. Binary Relational Operators in Java  less than  <less than  <=less than or equal to  > greater than  >= greater than or equal to  == equal to  !=not equal to  less than  <less than  <=less than or equal to  > greater than  >= greater than or equal to  == equal to  !=not equal to Binary Equality Operators in Java

11. Binary Logical Operators  &AND  |OR  ^Exclusive OR  &&Short Circuit AND  ||Short Circuit OR  !Not  &AND  |OR  ^Exclusive OR  &&Short Circuit AND  ||Short Circuit OR  !Not Unary Logical Operators

12. Bitwise Operators in Java  & AND  |Inclusive OR  ^Exclusive OR  <<Left Shift  >>Right shift (sign extension)  >>>Right shift (zero extension)  Compares integer values bit by bit  Evaluated right to left  & AND  |Inclusive OR  ^Exclusive OR  <<Left Shift  >>Right shift (sign extension)  >>>Right shift (zero extension)  Compares integer values bit by bit  Evaluated right to left

13. Assignment Statements  Basic statement used to perform calculations  Form: result = expression;  Example: X = X + X * Y;  Basic statement used to perform calculations  Form: result = expression;  Example: X = X + X * Y;

14. Assignment operators  A = B assign value of expression B to variable A, store result in A  A += B add the value of expression B to variable A, store result in A  A -= B subtract the value of expression B from variable A, store result in A  A *= B multiply the value of expression B by variable A, store result in A  A /= B divide the value of expression B by variable A, store result in A  A = B assign value of expression B to variable A, store result in A  A += B add the value of expression B to variable A, store result in A  A -= B subtract the value of expression B from variable A, store result in A  A *= B multiply the value of expression B by variable A, store result in A  A /= B divide the value of expression B by variable A, store result in A

15. Precedence of operators in Java  ( ) []. innermost first  ++ -- (pre) + - ! (unary) (right to left)  * / %  + -  > >>>  >=  == !=  &  ^  |  &&  ||  =  += -= *= /= %=  ( ) []. innermost first  ++ -- (pre) + - ! (unary) (right to left)  * / %  + -  > >>>  >=  == !=  &  ^  |  &&  ||  =  += -= *= /= %=

16. Data Types  Data Type  A set of values plus a set of operations on those values  A crucial concept on modern programming  Data Type of a variable determines how its memory cells are interpreted  Data Type of a variable indicates the size of the memory cell allocated for the variable  Data Type  A set of values plus a set of operations on those values  A crucial concept on modern programming  Data Type of a variable determines how its memory cells are interpreted  Data Type of a variable indicates the size of the memory cell allocated for the variable

17. Primitive Data Types

18.  Floating-Point Data Types  Float: single precision = 6 or 7 digits range -3.4*10 38 to 3.4*10 38  Double: double precision = 15 digits range -1.7*10 308 to 1.7*10 308  Arithmetic and relational operators  Boolean Data Types:  two values TRUE and FALSE  Logical operators  Floating-Point Data Types  Float: single precision = 6 or 7 digits range -3.4*10 38 to 3.4*10 38  Double: double precision = 15 digits range -1.7*10 308 to 1.7*10 308  Arithmetic and relational operators  Boolean Data Types:  two values TRUE and FALSE  Logical operators

19. Integral Data Types

20. Values and Memory Allocation for Integral Data Types