CSE 1341 Principles of Computer Science I

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CSE 1341Principles of Computer Science I

• Note Set 4

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QA about Program 1
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Semester Overview

• Functions
• Character File I/O
• Arrays
• Pointers and Dynamic Memory Allocation
• Structures/Records
• Binary File I/O

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Lecture Overview

• Using inline functions to improve performance
• Function Overloading

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• Inline Functions

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Inline Example

• inline float circleArea(float rad)
• return(3.14159 rad rad)
• int main()
• cout.precision(2)
• cout.setf(iosfixed)
• for (float r1.0rlt2.0r0.1)
• coutltltRadius ltltrltlt\tArea
• ltltcircleArea(r)ltltendl
• return 0

Compiler could replace with 3.14159rr
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Inline Functions

• Compiler may replace function call with actual
  code from inline function
• Should only be used with very small functions
• Can potentially gain performance increase, but
  can cause code to become bloated
• When in doubt, dont inline a function

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• Function Overloading

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Function Overloading

• Two functions that have the same name, but
  different signatures
• Signature is
• Name of the function
• Data types of the functions parameters in the
  proper order

int square(int) double square(double)
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Function Signatures
void f(int, float, char) void f(char, char) int
f()
Signature can be ascertained from function
prototype.
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Example w/ Overloaded Functions

• int square(int)
• int square(float)
• int main()
• int userInt
• float userFloat
• cout ltlt Enter an Integer and Float
• cin gtgt userInt gtgt userFloat
• cout ltlt endl ltlt square(userInt) ltlt
• ltlt square(userFloat)
• return 0

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Overloading contd
int main() int userInt float userFloat
. . . coutltlt square(userInt) ltlt
square(userFloat) . . .
int square(int number) return (number
number) float square(float number) return
(number number)
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Overloaded Quiz

• int someFunction(int)
• float someFunction(int) yes or no
• void someFunction(int, short)
• void someFunction(float) yes or no
• int someFunction(int)
• int someFunction(float) yes or no
• int someFunction(int)
• int somefunction(int, int) yes or no

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Example

• int someFunc(int, char)
• int someFunc(char, char, float)
• int main()
• int x, y
• x someFunc(c, v, 4.5)
• y someFunc(3, q)
• return 0

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exit()

• exit()
• causes program to terminate
• provide an integer argument as exit code
• include ltcstdlibgt

void function() cout ltlt BEGIN ltlt endl
exit(0) cout ltlt WILL NEVER BE PRINTED ltlt
endl
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Stubs

• Useful for testing and debugging
• Stub
• dummy function that is called instead of the
  actual function in represents
• usu. displays test message

void showFees(double memberRate, int months)
cout ltlt showFees called with arguments cout
ltlt memberRate ltlt ltlt months ltlt endl
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Questions??

• ?