ReviewC1toC5
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Type

Chapter

Description

C++

Input

1

input, getting information from outside world (user)

cin >> age; //extraction

cin >> x >> y;

Output

1

output, getting information/results to outside world (screen)

cout << age; //insertion

cout << x << 'a' << 123 << endl;

cout << x << "a" << 123 << endl;

 

1

declare variables

int age;

int height, weight;

int x = 3;

float y = 3.5f; //1.65 as 0.165x10+1

int *p;

p = &age;

 

1

assignment

age = 50; //

height = weight = 50;

height = (weight = 50);

 

1

comments

//.....comment

int a; //.....comment

/*

.....comments...........

.........

*/

 

1

if selection

if (age > 30)

cout << "Too old";

 

1

if/else selection

if (age > 30)

cout << "Cold";

else

cout << "Okay";

 

1

beginning main program

void main(void)

int main()

int main(int argc, char **arg)

 

1

returning a value from a function

return x;

return;

int add(int a, int b)

{

return a+b;

}

float add(float a, float b)

{

return a+b;

}

x=add(4,5);

y=add(4.5f,6.5f);

return a+b;

return 1;

return;

void swap(int &a, int &b)

{

if (a != b)

{

int t = a;

a = b;

b = t;

}

}

swap(x,y);

 

1

having access to library of functions

#include <iostream.h>

#include <math.h>

 

1

newline

cout << ‘\n’

 

1

horizontal tab—move the screen cursor to the next tab stop

‘\t’

 

1

position cursor to the beginning of the current line

‘\r’

 

1

alert; sound the system bell

‘\a’

 

1

addition

f + 7;

a = f+7;

 

1

subtraction

p - c

 

1

multiplication

b * m

 

1

division

x / y

1/2

1.0/2

floating point?

0.000006234

0.6234 x 10-5

 

1

modulus

r % s

a = 5%2;

a = rand()%7;

a = 1 + rand()%6;

a = 15 + rand()%11;

 

1

equal to

x == y

if (x==y)

cout << "Equal\n";

if (x=y)

cout << "Equal\n";

if (5==x)

cout << "Equal\n";

 

1

not equal to

x != y

 

1

greater than

x > y

 

1

less than

x < y

 

1

less than or equal to

x <= y

 

1

integer division

x / y

 

1

exponentiation

z=pow(x, y); //requires <math.h>

 

1

avoiding naming conflicts

using namespace std;

 

2

conditional expression

F = (gr >= 60) ? ‘A’ : ‘B’;

if (gr >= 60)

F = ‘A’;

else

F = ‘B’;

cout << ((gr >= 60) ? 'A':'B');

loop

2

while structure

int product = 1;

while (product <= 1000)

product = 2 * product;

int product = 1;

while (product <= 1000)

{

product = 2 * product;

cout << product << ' ';

}

 

2

c = c + 7

c += 7;

c=c+1; //c += 1; c++;

 

2

d = d - 7

d -= 7;

 

2

preincrement

++Counter;

i = 1;

x = a[++i]; //x = a[2];

i = 1;

x = a[i++]; //x = a[1];

 

2

postdecrement

Counter--

i = 1;

x = a[i++]; //postincrement x = a[1]

 

2

switch structure

grade = 'A';

switch (grade)

{

case'A':

++aCount; break;

case'B':

++bCount; break;

default:

cout << "Error\n";

}

 

2

do/while

counter = 1;

do

{

cout << counter << " ";

counter++;

}

while (counter <= 10);

 

3

exponential function

exp(x)

 

3

natural log

log(x)

 

3

base ten log

log10(x)

 

3

square root of x

sqrt(x)

 

3

function

int square(int y)

{

return y*y;

}

...

i = square(2);

...

void square(int x, int &y )

{

y = x*x;

}

i=2;

square(i, j);

 

3

prototype

int square(int y);

int square(int);

int sum(int, int);

void swap(int &, int &);

void swap(int &x, int &y);

void swap(int &x, int &y)

{

if (x==y)

return;

else

{

int temp = x;

x = y;

y = temp;

}

}

int square(int z)

{z=9; return z*z;}

x=3;

y=square(x); // inside square x=35;

cout << x << ' ' y;//x will remain 3

int square(int &z)

{z=9; return z*z;}

x=3;

y=square(x); // inside square x=35;

cout << x << ' ' y; //x will be 9

 

3

standard library header files

<iostream.h>

<ctype.h>

<float.h>

<limits.h>

<math.h>

<stdio.h>

<stdlib.h>

<string.h>

<time.h>

<iomanip.h>

<fstream.h>

 

3

random number

i = rand(); //requires <stdlib.h>

i = rand()%100; // [0,99]

i = rand()%6 + 1; //[1,6]

for(int ij=0;ij<5;ij++)

cout << rand()%100 << endl;

 

3

randomizing

seed = 16;

srand(seed);

srand(time(NULL)); //stdlib.h, time.h

i = rand();

i = rand();

for (int j=0; j<100; j++)

cout << (rand()%6 + 1) << endl;

1 2 1 5 4 2 ...

2 6 1 1 3 2 …

 

3

data types

long double

double

float

unsigned long int (unsigned long)

long int (long)

unsigned int (unsigned)

int

unsigned short int (unsigned short)

short int (short)

unsigned char

short

char

 

3

enumeration

enum Status {HEAD, TAIL};

//HEAD=0, TAIL=1

Status Result; // int a;

Result = HEAD;

enum Days {Sun, Mon, Tue};

Days today;

today = Sun;

 

3

storage class specifiers

auto int x;

register int y;

extern int a;

static int b;

 

3

scope rules

function scope

file scope

block scope

function-prototype scope

class scope

 

3

recursion

n! = n * (n-1)!, 0!=1, 1!=1

5! = 5*4*3*2*1

unsigned long fact(int n)

{

if (n <= 1)

return 1;

else

return (n * fact(n-1));

}

cout << fact(5) << endl;

 

3

functions with empty parameter lists

void DisplayHello(void)

{

cout << "Hello!" << endl;

}

DisplayHello();

 

3

inline functions

inline int Double(int x) {return 2*x;}

inline int Double(int x)

{

return 2*x;

}

 

3

reference parameter

void swap(int &x, int &y)

{

int temp = x;

x = y;

y = temp;

}

swap(a, b);

 

3

reference variable (alias)

int x = 3;

int &y = x; //y is an alias of x

 

3

default arguments

int area(int len=1, int wid=2); //default values only in prototype

int area(int len, int wid)

{

return len * wid;

}

...

cout << area(3) << endl;

cout << area(3,3) << endl;

cout << area() << endl; //call

…

 

3

unary scope resolution operator

cout << x << endl; //local value of x

cout << ::x << endl;//global value of x

 

3

function overloading

int Sum(int x, int y)

{return x+y;}

float Sum(float x, float y)

{return x+y;}

int Sum(int x, int y, int z)

{return x+y+z;}

a = Sum(3,4,5);

 

3

function templates

template <class T>

T Sum(T x, T y)

{

return x + y;

}

...

cout << Sum(1,2) << endl;

cout << Sum(1.2f, 3.5f) << endl;

cout << Sum(10,21) << endl;

…

 

3

constants

const int MAX_COUNT = 10;

 

4

Arrays

const int MAX =5000;

int a[MAX]; //a[0], a[1], …, a[MAX-1]

for (int i=0; i<MAX; i++)

cin >> a[i]

int s = 0;

for (int i=0; i<MAX; i++)

s = s + a[i];

for (int i=0; i<MAX; i++)

cout << a[i] << ' ';

 

4

declaring one-dimensional arrays

int c[10];

int a[5], b[7];

int x[5] = {4, 2, 7, 3, 6};

int y[] = {4, 2, 7, 3, 6};

int z[10] = {0};

char name[40];

char city[] = "Pittsburg";

char city2[] = {'J', 'o', 'p', '\0'};

 

4

passing arrays

void sort(int array[], int n); //prototype

sort(a, 10); //call

void sort(int array[], int n)

{

if (n<=1)

return;

int i, j;

for (i=1; i<=n-1; i++)

{

for (j=0; j<n-1; j++)

if (array[j]>array[j+1])

swap(array[j], array[j+1]);

}

}

 

4

multi-dimensional arrays

int a[2][3] = {{1, 2, 3}, {4, 5, 6}};

// 1 2 3

// 4 5 6

 

5

Pointer Variable Declarations and Initialization

int *countPtr, count;

float *sPtr, *yPtr;

//John is near Tom

 

5

Pointer Operators

int y = 5;

int *yPtr;

yPtr = &y;

cout << *yPtr;

*yPtr = 9;

//assign 9 to the variable pointed to by yPtr

cout << y;

 

5

Calling Functions by Reference

void cube(int *p);

cube (&n);

void square(int &q);

square(n);

 

5

Using the const Qualifier with Pointers

void convToUpper(char *c);

void printStr(const char *p);

int lengthStr(const char *ptr);

 

5

Pointer Expressions and Pointer Arithmetic

char s[] = "Pittsburg";

char *ptr;

ptr = s;

ptr++;

ptr = ptr + 2;

ptr--;

 

5

The Relationship Between Pointers and Arrays

int b[5]; // 12, 56, 29, 17, 99

int *bPtr;

bPtr = b; // bPtr = &b[0];

x = *bPtr; // x = b[0];

x = *(bPtr+1); // x = b[1];

x = *(bPtr+2) // x = b[2]; //29

x = *bPtr + 2; // x = b[0] + 2;

bPtr++;

 

5

Arrays of Pointers

char *s[] = {"Pittsburg", "Joplin"};

char **s = {"Pittsburg", "Joplin"};

s[0] points to "Pittsburg"

s[1] points to "Joplin"

 

5

String Manipulation Functions

char *strcpy(char *s1, const char *s2);

char s1[10], s2[]="Pittsburg";

strcpy(s1, s2);

s1=s2; //misleading

//length of s2

int a;

a = strlen(s2);

char *p1;

p1 = s1;

a = 0;

while (*p1 != '\0')

{

a++;

p1++;

}

if (strcmp(s1, s2)<0) ...

 

6

Structure Definitions

struct TimeType

{

int hour;

int minute;

int second;

};

TimeType start, end;

start.hour = 11;

cout << start.hour;

TimeType a[5];

a[0].hour=8; //not a.hour[0]=8;

a[0].minute = 3;

struct studentRecType

{

char name[10+1];

int age;

float gpa;

};

studentRecType srecs[7000];

strcpy(srecs[0].name, "john");

srecs[0].age = 26;

srecs[0].gpa = 4.0f;

 

int hour[5];

int minutes[5];

int seconds[5];

 

6

Implementing Time with a class

class Time

{

private:

int hour;

int minute;

int secons;

public:

Time(void);

void setTime(int h, int m, int s);

};

Time start, end;

start.hour = 11;//not allowed

cout << start.hour;//not allowed