Programming in c function

Programming in c function

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  COMPUTER PROGRAMMING INTRODUCTION TO FUNCTION CEN204
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  2 2 P r es e n t e d B y, C E N 6 8 B 1 G r o u p - 3 • Pranta Biswas • Md. Saiful Hasan Bhuiyan • Pallob Sikdar • Rajib Roy • Md. Lekhon Miah • Parvez Ahmed
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  3 S F U NC T I O N Add a Footer 3 A complex problem is often easier to solve by dividing it into severalsmallerparts,eachofwhichcanbesolvedbyitself. Thisiscalledstructured programming. Thesepartsaresometimesmadeintofunctions inC/C++. main()thenusesthesefunctions tosolvetheoriginalproblem.
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  4 Add a Footer4 F U N C T I O N D E F I N I T I O N The function definition can be placed anywhere intheprogramafterthefunction prototypes. Ifafunctiondefinitionisplacedinfrontofmain(), there is no need to include its function prototype.
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  5 Add a Footer5 F U N C T I O N D E F I N I T I O N A function definition has the following syntax: <type> <function name>(<parameter list>){ <local declarations> <sequence of statements> } For example: Definition of a function that computes the absolute value of an integer: int absolute(int x){ if (x >= 0) return x; else return -x; }
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  6 S Add a Footer6 Functions separate the concept (what is done) from the implementation(howitisdone). Functionsmakeprogramseasierto understand. Functions can be called several times in the same program, allowingthecodetobereused. A D V A N TA G E O F F U N C T I O N
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  7 S Add a Footer7 C++ allows the use of both internal (user-defined) and external functions. Functionsmakeprogramseasierto understand. External functions (e.g., abs, ceil, rand, sqrt, etc.) are usually grouped into specialized libraries (e.g., iostream, stdlib, math, etc.) F U N C T I O N I N C / C + +
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  8 S Add a Footer8 C++programsusually havethefollowing form: U S E R - D E F I N E D F U N C T I O N S // include statements // function prototypes // main() function // function definitions
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  9 Add a Footer9 C++programsusuallyhavethefollowing form: E X T E R N A L F U N C T I O N S Function Description acos(x) Inverse cosine of x (in radians) Asin(x) Inverse sine of x (in radians) Atan(x) Inverse tangent of x (in radians) Sin(x) Sine of x (in radians) Cos(x) Cosine of x (in radians) Tan(x) Tangent of x (in radians) *Ceil(x) Ceiling of x (rounds up) Exp(x) Exponential of x (base e) Fabs(x) Absolute value of x *Floor(x) Floor of x (rounds down) Log(x) Natural logarithm of x (base e) *Pow(x,p) X to the power p Sqrt(x) Square root of x
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  10 10 F U NC T I O N I N P U T & O U T P U T RESULT PARAMETERS
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  11 Add a Footer11 The function prototype declares the input and output parametersofthefunction. F U N C T I O N P R O T O T Y P E Thefunctionprototype hasthefollowing syntax: <type> <function name>(<type list>); Example: A function that returns the absolute value of an integer is: int absolute(int);
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  12 ARGUMENTS/ PARAMETERS Add a Footer12 one-to-one correspondence between the arguments in a function call and the parameters in the function definition. int argument1; double argument2; // function call (in another function, such as main) result = thefunctionname(argument1, argument2); // function definition int thefunctionname(int parameter1, double parameter2) { // Now the function can use the two parameters // parameter1 = argument 1, parameter2 = argument2
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  13 Add a Footer13 Afunctioncallhasthefollowing syntax: <function name>(<argument list>) Example: int distance = absolute(-5); F U N C T I O N C A L L Theresultofafunctioncallisavalueoftype<type>
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  14 Add a Footer14 F U N C T I O N E X A M P L E
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  15 Add a Footer15 F U N C T I O N E X A M P L E
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  16 Add a Footer16 C O N C L U T I O N • Our program can determine the Diameter and Cross sectional Area of aReinforcementBar fromanyBarNumber. • This program is useful during designing a structure when only a Bar Numberisgiven. • Thisprogramisalsocanbeuseinestimatingofreinforcement. • It is essential for people in the shop and in the field to be able to identifyataglancethesizesofthebars.
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  17 Add a Footer17 F U N C T I O N