Compu 142

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Compu 142

• Computer Science I
• Java
• 2.1 2.2

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Due Today Wed. 6/27

• Reread 1.4-5
• Read 2.1-2
• Bring Windows Worksheets 2 3
• Exercises handwritten OK

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Whos new

• Previous handouts

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Questions

• From the Questionnaires
• Read
• Email

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Success

• Be here
• Read
• Ponder
• Homework
• Study buddies

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Flow of control (Ch. 1)

• Trace
• p.44 16 Strange
• Study FooBarBazMumble p. 33
• Expect on a quiz/test
• Study Infinite p. 36
• CtrlC

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Refinement (Ch. 1)

• Detailed structure
• Cure redundancy
• cone
• V
• box
• Finish Rocket

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Decomposition Example

• p. 50 3
• H\142\Song\ThereWasAnOldHacker.txt
• Structure
• Redundancy
• Pseudocode
• Comments Stubs

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Chapter 2 !!

• Data
• Information used by the program
• Must be stored in RAM
• Must be stored in binary
• How?
• Big issue in Computer Science

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Data in Java (2.1)

• Primitives
• Numbers
• Single letters
• True/false

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Data in Java

• Objects
• Strings of letters
• Shapes
• People
• Colors
• Odors
• ...

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Expressions Formulas

• Expression
• Value
• Set of ops that yield a value
• Evaluation
• Getting that value
• Operator
• Symbol that indicates the operation
• Operand
• The stuckee, the done unto

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Literal Data

• Typed into program
• whole number
• real number
• single character
• true, false
• a string of characters
• Wouldnt Excel be faster?

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Arithmetic Operators !!!

• Basic - /
• Grouping ( )
• Tracing

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Precedence (p. 60)

• PEMDAS
• no E
• unary operators ?
• Assignment () is last

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When you choose a data type (1)

• You actually choose
• How much space in RAM
• A convenient name for that space
• How to encode the data into binary
• How to decode the binary
• What operations are legal for that data

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Mixing Types Casting

• Java willtemporarily promote a value
• int to double
• char to int
• BUT not demote a value
• double to int
• int to char

• ?
• ?

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When you choose a data type (2)

• You actually choose
• How much space in RAM
• A convenient name for that space
• How to encode the data into binary
• How to decode the binary
• What operations are legal for that data

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Variables (2.2)

• Value can vary (change)
• Like Excel but maybe better

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Assignment

• Gets the value of

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Declaring
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String Concatenation

• System.out.println(Manny Moe)
• MannyMoe
• System.out.println(Manny 6)
• Manny6
• System.out.println(Manny 6 7)
• Manny67
• System.out.println(Manny A 7)
• Manny455

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Increment Decrement

• p. 75
• PTs ROT Separate statements

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Variables Mixing Types

• See slide 17

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Hands On -- review (Ch. 1)

• /--------------------\
• Phineas Taylor
• /--------------------\
• Phineas Taylor
• /--------------------\
• Phineas Taylor
• /--------------------\
• Plan code compile run
• Comments your name date
• Send code to printer (use your name 142 HandsOn)

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For Tomorrow 6/29

• Reread 2.1-2
• Read 2.3-4
• Bring short programs 5 9
• handwritten OK