Introduction to Programming

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Introduction to Programming

• Lecture 45

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Assignment Operator
A B
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Class Matrix

• const Matrix operator ( const Matrix m )
  

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Assignment Operator
( A B ) C
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Self Assignment
A A
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Class Matrix

• const Matrix Matrix operator ( const
  Matrix m )
• if ( m ! this)
• if ( numRows ! m.numRows numCols !
  m.numCols )
• delete elements
• elements new ( double ) m.numRows
  
• for ( int i 0 i lt m.numRows i
  )
• elements i new double
  m.numCols

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Class Matrix

• numRows m.numRows
• numCols m.numCols
• for ( int i 0 i lt numRows i )
• for ( int j 0 j lt numCols j )
  
• elements i j
  m.elements i j
• return this

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Addition Operator
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Addition Operator
A B
Both A and B are Matrices
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Class Matix

• Matrix Matrix operator ( Matrix m ) const
• // Check for conformability
• if ( numRows m.numRows numCols
  m.numCols )
• Matrix temp ( this )
• for ( int i 0 i lt numRows i )
• for ( int j 0 j lt numCols j )
• temp.elements i j
  m.elements i j
• return temp
• Matrix temp ( this )
• return temp

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Operator
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Operator
A B
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Class Matrix

• const Matrix Matrix operator ( Matrix m
  )
• this this m
• return this

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Class Matrix

• Matrix Matrix operator ( double d ) const
• Matrix temp ( this )
• for ( int i 0 i lt numRows i )
• for ( int j 0 j lt numCols j )
• temp.elements i j d
• return temp

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Class Matrix

• Matrix operator ( double d , Matrix m )
• Matrix temp ( m )
• for ( int i 0 i lt temp.numRows i
  )
• for ( int j 0 j lt temp.numCols
  j )
• temp.elements i j
  d
• return temp

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Operator
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Class Matrix

• Matrix Matrix operator ( const Matrix m )
• Matrix temp ( numRows , m.numCols )
• if ( numCols m.numRows )
• for ( int i 0 i lt numRows i )
• for ( int j 0 j lt m.numCols j
  )
• temp.elements i j 0.0
• for ( int k 0 k lt numCols k
  )
• temp.elements i j
  elements i k m.elements k j
• return temp

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Class Matrix

• Matrix Matrix operator ( double d ) const
• Matrix temp ( this )
• for ( int i 0 i lt numRows i )
• for ( int j 0 j lt numCols j )
• temp.elements i j d
• return temp

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Matrix / d Check d 0 ?
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ltlt Insertion Operator
gtgt Extraction Operator
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Where m is an object of the class Matrix
cin gtgt m
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Class Matrix

• istream operator gtgt ( istream is , Matrix
  m )
• m.input ( is )
• return is

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Class Matrix

• ifstream operator gtgt ( ifstream is , Matrix
  m )
• m.input ( is )
• return is

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Class Matrix

• ostream operator ltlt ( ostream os , Matrix
  m )
• m.output ( )
• return os
• ofstream operator ltlt ( ofstream os , Matrix
  m )
• m.output ( os )
• return os

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• main ( )
• Matrix m ( 3 , 3 )
• m.output ( )

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Template for Matrix Class
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Rules for Programming

• Sequences
• Decisions
• Loops

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Variable
Variable is a name for a value
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Pointer

• Pointer is the address
• of a location in the
• memory

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Arrays
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Decisions
Or if ( condition
) statement ( s ) else if ( condition
) statement ( s )
if ( condition ) statement ( s )
Or if ( condition
) statement ( s ) else statement
( s )
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Repetition Structure

• There are three kinds of Loops in C Language
• while
• do while
• for

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Classes and Objects
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Classes and Objects

• Object.member

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Garbage Collection
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Truth Table
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• Structured Query Language
• SQL

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• Optimizer