nothing worth knowing can be taught

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Lecture 8
nothing worth knowing can be taught Oscar Wilde
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Quiz 2 solutions
3
One more nuance on input...

• Cant read in first couple of integers, then
  couple of characters in one read/readln statement

4
More on loops

• Changing variables
• Changing loop count
• Changing max

5
Average revisited

• PROGRAM Average
• VAR iSum, iCount, iGrade, iNumberOfGrades
  integer
• BEGIN
• write( 'Please enter the number of grades '
  )
• readln( iNumberOfGrades )
• iSum 0
• FOR iCount 1 TO iNumberOfGrades DO
• BEGIN
• write( 'Enter grade ', iCount, ' ' )
• readln( iGrade )
• iSum iSum iGrade
• END
• writeln( 'Your average is ', (iSum /
  iNumberOfGrades)22 )
• END.

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Nested loops

• Why do we need this???
• For example, compute class average!

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Class average

• PROGRAM ClassAverage
• VAR iGradeCount, iStudentCount, iGrade, iSum
  integer
• iNumberOfGrades, iNumberOfStudents integer
• BEGIN
• write( 'Please enter the number of students
  ' )
• readln( iNumberOfStudents )
• write( 'Please enter the number of grades '
  )
• readln( iNumberOfGrades )
• iSum 0
• FOR iStudentCount 1 TO iNumberOfStudents
  DO
• FOR iGradeCount 1 TO iNumberOfGrades DO
• BEGIN
• write( 'Enter grade ',
  iGradeCount, ' of student ', iStudentCount, ' '
  )
• readln( iGrade )
• iSum iSum iGrade
• END
• writeln( 'Class average is ',
• (iSum / (iNumberOfGrades
  iNumberOfStudents) )22 )
• END.

8
Triangle program

• PROGRAM Triangle
• USES Crt
• VAR iNumberOfLines, iNumberOfColumns integer
• iLoopCount1, iLoopCount2, iNumberOfStars
  integer
• BEGIN
• ClrScr
• iNumberOfLines 10
• iNumberOfColumns 20
• FOR iLoopCount1 1 TO iNumberOfLines DO
• BEGIN
• iNumberOfStars 2iLoopCount1 -
  1
• write( ' ' iNumberOfColumns - (
  iNumberOfStars DIV 2 ) )
• FOR iLoopCount2 1 TO
  iNumberOfStars DO
• write( '' )
• writeln
• END
• END.

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Homework

• Read Chapter 5 sections 4 and 10
• Program 3 Page 204 15 a,b
• due Wed. October 14

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Programs from this lecture

• Changing variables inside the loop
• Changing loop counter and boundary
• Mixed input
• Personal average
• Class average
• Triangle