Beginning to Program Variables, Etc'

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Beginning to ProgramVariables, Etc.

• Computer Programming 1-2

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Variables
Names we give to storage locations in RAM.
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Variables
Names we give to storage locations in RAM.
Length
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Variables
Names we give to storage locations in RAM.
Length Width
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Variables
Names we give to storage locations in RAM.
Length Width Area
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Variable names

• Must begin with a letter
• Should be descriptive and meaningful
• May not contain spaces or special characters

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Valid or Invalid??
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Assignment Statements

• Use LET to give a variable a value.

LET variable ___
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LET Statement Examples

• LET Age 17
• LET Age 6.5
• LET Cost 4.99
• LET TaxRate .07125
• LET NegNumber -4

No or commas!
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Use LET Statements for

• INPUT to store a value in RAM and give its
  location a name so it can be used later.
• PROCESSING calculations

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Computer Calculations
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Computer Calculations
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Computer Calculations
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Computer Calculations
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Write these expressions in Basic

• 4x 5y 3 4 x 5 y 3

• 6c
• 7r 5
• a2b2

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Write these expressions in Basic

• 4x 5y 3 4 x 5 y 3
• 6c 6 c
• 7r 5 7 r 5
• a2b2 a 2 b 2
• a a b b

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Evaluate these expressions

• 1 2 3
• 5 (4 3) / 2
• 1 (2 3) 2 - 1

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LET Statement Examples

• LET Total a b
• LET Half Num / 2
• LET GrossPay Hours Rate

Variable on left formula on right
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Hey! Not all data is numeric.
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What about words and names?
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Think of some data that is not numeric

• Words
• Names
• What else??

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Non-numeric data are called strings.
String variables end with
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LET Statement Examples
Variable ends with string in

• LET Word Hi
• LET Name Sue
• Let Title War and Peace

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What else do we need? We can...

• Use LET for Input
• Use LET for Processing
• Use PRINT for Output

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