READ and DATA Statements

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READ and DATA Statements

• Computer Programming 1-2
• 2000-2001

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READ and DATA Statements

• Use when there is a large volume (a lot) of
  input.
• READ actually performs the input.
• DATA lists values to be entered by READ.
• READ Name, Age
• DATA Nancy, 15

Instead of LET NameNancy LET Age15
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Data is entered into main memory (RAM) with a
variable assigned to represent it later in the
program.
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READ and DATA Statements

• READ statements go in the main programwherever
  the input step is to occur.
• READ statements find DATA statements and match
  variables and values in the order listed.

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READ and DATA examples

• READ Car, Miles, Gallons
• DATA Buick, 290, 14
• READ Score1, Score2, Score3
• DATA 100, 200, 300

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Rules for READ and DATA

• Variables in _____ statements are matched to
  constants in _____ statements.
• _____ statements contain one or more variables,
  separated by _____.
• _____ statements contain one or more constants,
  separated by _____.

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Rules for READ and DATA

• DATA statements are placed after the END
  statement.
• The number of variables in READ should match the
  number of constants in DATA.
• The data type of the variables in READ must match
  the data type of the constants in DATA,
• AND THEY MUST BE IN THE SAME ORDER!

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Errors with READ and DATA

• READ Song, Sales
• DATA Hey, Jude, 1000000
• DATA Hey, Jude, 1000000
• DATA 1000000, Hey, Jude
• DATA Hey, Jude
• DATA 1000000

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Errors with READ and DATA

• Items listed in READ and DATA statements must
  match in number and by data type or you will get
  a syntax error.
• There must be enough DATA items to match with the
  READ variables or you will get an out of data
  error.

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Show the output

• READ A1, A2, A3
• Sum A1 A2 A3
• PRINT Sum Sum
• END
• DATA 15, 8, 2

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Show the output

• READ P, Moon
• READ Num
• PRINT P has at least
• PRINT Num Moon
• END
• DATA Jupiter, moons, 16

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Show the output

• READ A, B
• PRINT A is a B
• READ C
• PRINT A is a C
• END
• DATA Pluto, dog, planet

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Debug

• READ Name, Age
• PRINT Name isAgeyears old.
• END
• DATA Jody, 5

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Debug

• READ Lngth, Wdth
• LET Area Lngth Wdth
• PRINT Area Area
• END
• DATA 120, 86

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Debug

• READ Year, Car
• PRINT I have a Year Car
• END
• DATA Toyota, 1998

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You try it!

• Change your grade program to use READ and DATA
  instead of LET for input. Save with the same
  name.
• Change two other LET or INPUT programs. Resave.
• MYINFO.BAS

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