1. Comp 114 Foundations of Programming Instructor: Prasun Dewan

2. Topics Assumed & Reviewed Types –int, double, char, String Variables, constants, expressions Arrays Assignment, conditionals, loops Procedures/Functions/Subroutines/Methods Parameters/arguments

3. Hello World

4. package warmup; public class AHelloWorldGreeter { public static void main (String[] args) { System.out.println ("Hello World"); } Array of user-supplied arguments main header directory/library Keyword Predefined Programmer- defined

5. Main Arguments user-supplied argument

6. Main Arguments package warmup; public class AnArgPrinter { public static void main (String[] args) { System.out.println (args[0]); } First argument args[0] args[1] Second argument...

7. Main Arguments user- supples no argument package warmup; public class AnArgPrinter { public static void main (String[] args) { System.out.println (args[0]); } program refers to argument array element exception!

8. Safe Arg Printer

9. Safe Arg Printer (edit in class) package warmup; public class ASafeArgPrinter { public static void main (String[] args) { //args.length gives number of elements in args array. }

10. Safe Arg Printer package warmup; public class ASafeArgPrinter { public static void main (String[] args) { if (args.length == 1) System.out.println (args[0]); else { System.out.println("Illegal no of arguments:" + args.length + ". Terminating program"); System.exit(-1); }

11. if-else Statement if ( ) else

12. if-else Statement true false

13. Compound Statement if (args.length == 1) System.out.println (args[0]); else { System.out.println("Illegal no of arguments:" + args.length + ". Terminating program"); System.exit(-1); }

14. Nested if-else public static char toLetterGrade (int score) { if (score >= A_CUTOFF) return 'A'; else if (score >= B_CUTOFF) return 'B'; else if (score >= C_CUTOFF) return 'C'; else if (score >= D_CUTOFF) return 'D'; else return 'F'; }

15. Nested if-else if (score >= A_CUTOFF) return 'A'; else if (score >= B_CUTOFF) return 'B'; else if (score >= C_CUTOFF) return 'C'; else if (score >= D_CUTOFF) return 'D'; else return 'F';

16. Nested if-else

17. If Statement if (args.length = = 1) System.out.println (”args[0]”); if ( ) ;

18. Printing Multiple Arguments

19. Printing Multiple Arguments (edit in class) package warmup; public class AnArgsPrinter { public static void main(String[] args){ }

20. Printing Multiple Arguments package warmup; public class AnArgsPrinter { public static void main(String[] args){ int argNo = 0; while (argNo < args.length) { System.out.println(args[argNo]); argNo++; }

21. if vs. while Statement if ( ) ; while ( ) ;

22. if Statement true false

23. while Statement true false

24. while loop true false

25. Scanning Problem

26. char Constants char {letters, digits, operators...} ‘a’ ‘A‘ ‘1’ ‘< ‘ ‘’ 16 bits ‘ ‘’’ ‘\’’ Escape sequence ‘\n’ newline ‘ ‘\’ ‘\\’

27. Useful Escape Sequences

28. Ordering Characters ‘’‘a’…. position in ordered character list ordinal number (integer code) ….

29. Ordering Characters ‘’‘a’…. ‘b’‘c’‘z’…. ‘’‘A’…. ‘B’‘C’‘Z’…. ‘’‘0’…. ‘1’‘2’‘3’…. ‘a’ > ‘b’  false ‘B’ > ‘A’  true ‘4’ > ‘0’  true ‘0’ > ‘’  true ‘a’ > ‘A’  ??? ‘a’ > ‘0’  ???

30. Converting between Characters and their Ordinal Numbers (int) ‘a’  ordinal number of ’a’ (char) 55  character whose ordinal number is 55 (int) ‘’  0 0 (char) 0  ‘’ (int) ‘d’  ??? (char) 1  ??? (char) -1 (int) ‘c’ - (int) ‘a’  2 2 ‘c’ - ‘a’  2 2 Implicit cast to wider type (char) (‘c’ - 2)  ‘a’ (char) (‘A’ + 2)  ‘C’ (char) (‘C’ - ‘A’ + ‘a’)  ‘c’

31. String constants String{sequences of characters} “hello” “123” “hello 123” “a” variable size ‘a’ “” “hello\n\n123” “\”“\\” Object Type

32. Accessing String Components String s = “hello world”; s[0] s[1]... s.charAt(0)  ‘h’ s.charAt(1)  ‘e’ s.charAt(-1) s.charAt(11) StringIndexBounds exceptiom index s.length()  11 “ ”.length()  1 1  0 0

33. Accessing SubString “hello world”.substring(4,7)  s.charAt(beginIndex).. s.charAt(endIndex-1) s.substring(beginIndex, endIndex)  “o w” “hello world”.substring(4,4)  “” “hello world”.substring(7,4) StringIndexBounds exceptiom

34. String Processing int i = 0; while (i < s.length()) { System.out.println (s.charAt(i)); i++; } prints each character on separate line

35. Dissecting a Loop int i = 0; while (i < s.length()) { System.out.println (s.charAt(i)); i++; } loop condition loop body

36. Finer-grained Dissection int i = 0; while (i < s.length()) { System.out.println (s.charAt(i)); i++; } loop condition real body Resetting loop variable initalizing loop variables for (int i=0; i<s.length(); i++) System.out.println(s.charAt(i));

37. Meaning of For Loop S1; while ( E) { S3; S2; } for (S1; E; S2) S3 for (; E; S2) S3 while ( E) { S3; S2; } for (; E; ) S3 while ( E) { S3; } for (; ; ) S3 while ( true) S3;

38. Scanning Problem

39. Scanning Scanning image for text. Scanning frequencies for radio stations. Finding words in a sentence Finding identifiers, operators, in a program

40. Scanning JohnF.Kenndye token Input stream Token Stream token

41. Algorithm JohnF.Kenndye marker 0 Output: J

42. Algorithm JohnF.Kenndye marker 1 Output: J String inputLine

43. Algorithm JohnF.Kenndye marker 2 Output: J

44. Algorithm JohnF.Kenndye marker 5 Output: JF

45. Algorithm JohnF.Kenndye marker 6 Output: JF

46. Algorithm JohnF.Kenndye marker 8 Output: JFK

47. Algorithm JohnF.Kenndye marker 9 Output: JFK

48. Algorithm JohnF.Kenndye marker 14 Output: JFK

49. Solution (edit in class) package warmup; public class AnUpperCasePrinter { public static void main(String[] args){ }

50. Solution package warmup; public class AnUpperCasePrinter { public static void main(String[] args){ if (args.length != 1) { System.out.println("Illegal number of arguments:" + args.length + ". Terminating program."); System.exit(-1); } System.out.println("Upper Case Letters:"); int index = 0; while (index < args[0].length()) { if (isUpperCase(args[0].charAt(index))) System.out.print(args[0].charAt(index)); index++; } System.out.println(); } public static boolean isUpperCase(char c) { return (c >= 'A') && (c <= 'Z'); } Function call Actual parameter Function definition Formal parameter

51. Creating JBuilder Project

55. Adding a Class

58. Editing the Class

59. Saving the Class

60. Running the Class

61. Viewing the Results

62. Running with arguments

68. Setting a break point

69. Running in debugging mode

70. Stopping at breakpoint

71. Examining the call stack

72. Navigating main parameters

73. Stepping to next statement (F8)

74. Stepping to next statement

75. Variable values

76. Stepping Over

77. Stepping Into (F9)

78. Stepping Out

79. Resuming normal execution

80. Program termination

81. Starting Eclipse

82. Specifying Projects Directory

83. No Projects Screen

84. Adding a New Project

85. Selecting Java Project

86. Entering Project Name

87. Switching to Java Perspective

88. Empty Project

89. Adding a Package (Optional Step)

90. Entering Package Name

91. Workspace, Project, Package  Folder Worskspace Project Package

92. Adding a New Class File

93. Naming the File.java suffix needed!

94. Empty File

95. Getting Rid of Welcome Pane

96. Editing the File

97. Saving the File

98. Running the Main Method

99. Output in Console Window Console

100. Running Main with Parameters

101. Setting Run Configuration

102. Run Configuration

103. Arguments Tab

104. Executing Debug

105. Setting a Break Point Double click where you want program to stop

106. Executing Debug

107. Starting the Debugger

108. Stopping at Breakpoint Debug Perspective Next statement to be executed

109. Examining Main Parameters Main Parameters

110. Stepping to next statement

111. Next Statement

112. New Output and Local Variable Index gets initialized println() executed

113. Step Over

114. Step Into Call stack Called method parameters

115. Step Return

116. Resume

117. Returning to Java Perspective

118. AReverseUpperCasePrinter

119. No bold face! No Outline!

120. Deleting File Will also delete from file system

121. Renaming

122. Adding.java suffix

123. Renamed File No bold face! No Outline!

124. Downloading ObjectEditor Software

127. Installing ObjectEditor Software

128. Must do this for each project!

129. Installing ObjectEditor Software

136. Testing ObjectEditor Software Any object instance!

137. Testing ObjectEditor Graphics

139. Adding a library in JBuilder

146. Location of All Libraries http://www.cs.unc.edu/~dewan/oe Use Internet explorer (not Netscape) to download files Latest library names –oe8.jar –shapes3.jar oe8.jar version 8 of oe.jar Sotware may have lots of bugs! Send me mail for workarounds bugs.

147. The end The rest are extra slides

154. Previous Main.class shown

158. Running Another Program with Parameters

166. Resume