Summary of basic C++-commands
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
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 explanations 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 integer Declaration (Example) short i1,i2; int i1,i2; long i1,i2; unsigned i1,i2; unsigned long i1,i2; real float f1,f2; double f1,f2; long double f1,f2; single character char c1,c2; string of characters string s1,s2; logical bool b1,b2;

Assignment (Example) i1 = 3;

f1 = 3.2; f2 = 2.1E-3;

c1 = ’R’ s1 = ”Farmer” b1 = true; b2 = false

Input And Output
Input/Output With Screen:
To be able to use the following commands you need to write
#include <iostream> using namespace std; at the beginning of your program: output: input:

cout << ”string of characters”; cout << variable; << endl; cin >> variable;

Input/Output With Files:
To be able to use the following commands you need to write
#include <fstream> at the beginning of your program: output: input:

ofstream outfilevariable ( ”outputfilename”,ios::out); outfilevariable << . . . will write into file with name outputfilename 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 <cmath>
#include <cstdlib> pow(x,y) xy sin(x) cos(x) tan(x) asin(x) sin−1(x) in range [−π/2, π/2] acos(x) cos−1(x) in range [0, π] atan(x) tan−1(x) in range [−π/2, π/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) 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 integers

= 5

Decision Statements
Comparison Operators:
==
!=
>
<
>=
<=
&&
||

= example: =
>
<
≥
≤ and and/or

Statements: if( condition ) { statements } if( condition ) { statements } else { statements } if( condition ) { statements } else if { statements } else { statements }

i1 == i2 i1 != i2 i1 > i2 i1 < i2 i1 >= i2 i1 <= i2
(i1 != i2)&& (i1 == i3)
(i1 == i2) || (i1 == i3)

switch ( casevariable ) { case value1a: case value1b:
{statements}
break; case value2a: case value2b:
{statements}
break; default: {statements}
}
Repetitions while (conditions) { statements } for ( init; conditions; update ){ statements } do { statements these statements are done before