**Summary of basic C++-commands / PDF**

**Compiling**

**To compile a C++-program, you can use either g++ or c++.**

g++ -o executable filename.out sourcefilename.cc

c++ -o executable filename.out sourcefilename.cc

e.g. g++ -o C++sample inout.out C++sample inout.cc

For the following commands you can find at the end of this summary sample programs.

Each command in C++ is followed by “;” . Carriage return has no meaning in C++.

**Comments**

Essential for the writing of clear programs are comments, which are explana-

tions for your program, and which are ignored by the compiler.

/* . . . */ puts the text . . . into comment (more than one line possible)

// . . . puts text . . . for rest of same line into comment

**Data Types**

Data Type Declaration (Example) Assignment (Example)

integer short i1,i2; i1 = 3;

int i1,i2;

long i1,i2;

unsigned i1,i2;

unsigned long i1,i2;

real float f1,f2; f1 = 3.2; f2 = 2.1E-3;

double f1,f2;

long double f1,f2;

single character char c1,c2; c1 = ’R’

string of characters string s1,s2; s1 = ”Farmer”

logical bool b1,b2; b1 = true; b2 = false

**Input And Output**

**Input/Output With Screen:**

To be able to use the following commands you need to write

#include

using namespace std;

at the beginning of your program:

output: cout << ”string of characters”;

cout << variable; << endl;

input: cin >> variable;

**Input/Output With Files:**

To be able to use the following commands you need to write

#include

output: ofstream outfilevariable ( ”outputfilename”,ios::out);

outfilevariable << . . . will write into file with name outputfilename

input: ifstream infilevariable ( ”inputfilename”,ios::in);

infilevariable >> . . . will read from file with name outputfilename

**Arithmetic Calculations**

Operations: + − ∗ /

Functions:

To be able to use all of the following functions you need to to write at the

beginning of your program:

#include

#include

pow(x,y) xy

sin(x)

cos(x)

tan(x)

asin(x) sin−1(x) in range [− /2, /2]

acos(x) cos−1(x) in range [0, ]

atan(x) tan−1(x) in range [− /2, /2]

sinh(x)

cosh(x)

tanh(x)

exp(x) ex

log(x) ln(x)

sqrt(x) √x

fabs(x) |x|

floor(x) largest integer not greater than x; example: floor(5.768) = 5

ceil(x) smallest integer not less than x; example: ceil(5.768) = 6

fmod(x,y) floating-point remainder of x/y with the same sign as x

x % y remainder of x/y, both x and y are integers; example: 7%5=.......

**Summary of basic C++-commands / PDF**