CS349 SE382 A1 C Programming Tutorial

Erin Lester

Description

CS349/SE382 A1 C Programming TutorialCS349/SE382 A1 C Programming TutorialErin LesterJanuary 2005CS349/SE382 A1 C Programming TutorialOutlineDi erences from C++CommentsVariable DeclarationsObjectsDynamic MemoryBoolean Typestructs, enums and unionsOther DierencesThe Event LoopCS349/SE382 A1 C Programming TutorialDierences from C++CommentsComments:I C has no one-line comments, only block comments/* this comment is valid in C *//* so isthis one */// but this one is noti = 2; // and neither is this oneCS349/SE382 A1 C Programming TutorialDierences from C++Variable DeclarationsVariable Declarations:I Variables must be declared at the beginning of code blocks,before any other types of statements#include void main(){char c;int i;i = 10 + 2;char *mystring = "Hello World"; /* not allowed */c = ’\n’;printf("%s%c", mystring, c);}CS349/SE382 A1 C Programming TutorialDierences from C++ObjectsObjects:I C has no objectsI use ADTs — remember cs246 — to be modularCS349/SE382 A1 C Programming TutorialDierences from C++ObjectsCreating a mock class/ADTStep 1. Create a header le for your mock classinclude:I empty structure declarationI function headers w/ structure as parameterCS349/SE382 A1 C Programming TutorialDierences from C++ObjectsCreating a mock class/ADTStep 2. Implement the code for the mock classin a ‘.c’ le:I include your ‘.h’ leI declare the structureI implement the ADT’s functionsCS349/SE382 A1 C ...

Informations

• Publié par: Mocher
• Nombre de lectures: 39
• Langue: English

Extrait

CS349/SE382

A1 C Programming Tutorial

CS349/SE382

A1

C

Erin

Programming

Lester

January

2005

Tutorial

CS349/SE382 A1 C Programming Tutorial Outline

Differences from C++ Comments Variable Declarations Objects Dynamic Memory Boolean Type structs, enums and unions Other Differences

The Event Loop

Comments:

I C has no one-line comments, only block comments

/* this comment is valid in C */ /* so is this one */ // but this one is not i = 2; // and neither is this one

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Variable Declarations:

#include <stdio.h> void main() { char c; int i; i = 10 + 2; char *mystring = "Hello World"; /* not allowed */ c = ’\n’; printf("%s%c", mystring, c); }

I Variables must be declared at the beginning of code blocks, before any other types of statements

CS349/SE382 A1 C Programming Tutorial Differences from C++ Objects

Objects:

I

I

C has no objects

use ADTs — remember

cs246

—

to

be

modular

CS349/SE382 A1 C Programming Tutorial Differences from C++ Objects

Creating a mock class/ADT

Step 1. Create a header file for include:

I empty structure declaration

I function headers w/ structure

your mock class

as parameter

CS349/SE382 A1 C Programming Tutorial Differences from C++ Objects

Creating a mock class/ADT

Step 2. Implement the code for the in a ‘.c’ file:

I include your ‘.h’ file

I declare the structure

I implement the ADT’ functions s

mock

class

CPA1grro/S4982E3irot iD laimmauTgnC3S cnseeffer+C D +rfmo icMeynammory

I the pointer can then be cast to the desired type and the memory assigned to a variable

I it returns a (void*) pointer to the memory allocated

I malloc() takes the number of bytes of memory as its parameter

I memory is allocated using ‘malloc()’

Dynamic Memory Allocation

Dynamic Memory:

DynamicMemory ffireneecfsorCm++ mmragTinorutl D ia/94383ESC1A2gorP

);

sizeof(

malloc(

)

myStruct

CS

{

...

myStruct *m (myStruct

= *)

typedef struct ... } myStruct;

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Freeing Dynamic Memory

free( m );

I memory is freed using ‘free()’ I free() takes the address of a non-null variable as its parameter I there is no garbage collection, so don’t forget to clean-up what you create

CS349/SE382 A1 C Programming Tutorial Differences from C++ Boolean Type

Boolean Type:

I

I

I

zero evaluates to false

non-zero evaluates to true

use typedef and defines to

mimic

the

boolean

type