https://robark.gitlab.io/basics/index.htmlBasics Compile, Link, ExecuteHugoen-usTue, 11 May 2021 17:35:38 +0000https://robark.gitlab.io/basics/helloworld/index.htmlTue, 27 Apr 2021 23:14:40 +0000https://robark.gitlab.io/basics/helloworld/index.htmlLesson 1: Hello World Explaining the differences between Python and C/C++.https://robark.gitlab.io/basics/various/index.htmlWed, 28 Apr 2021 22:50:31 +0000https://robark.gitlab.io/basics/various/index.htmlcout, datatypes, escape character, cin, promotion, type casting #include <iostream> // for cout using namespace std; //standard namespace // single line comment /* multi line comments */ int main(){ //https://en.cppreference.com/w/c/types/limits cout<<"hello"<<endl; int i(-1); i=2147483647; //biggest int i=-2147483648; //smallest int cout<<i<<endl; unsigned int ui(1); ui=4294967295; //biggest unsigned int ui = 0; //smallest unsigned int cout<<ui<<endl; long int l(999999999); short s(9); float f(-15.5); double d(9.11e-33); long double ld(4.4); char c('A'); char c2(65); unsigned char uc(255); bool b(false); //0 bool b2(true); //1 or bool b3(88); //anything other than 0 is true cout << "int "<<sizeof(i)<<endl; cout << "long "<<sizeof(l)<<endl; cout << "unsigned int "<<sizeof(ui)<<endl; cout << "short "<<sizeof(s)<<endl; cout << "float "<<sizeof(f)<<endl; cout << "double "<<sizeof(d)<<endl; cout << "long double "<<sizeof(ld)<<endl; cout << "char "<<sizeof(c)<<endl; cout << "char c2 = "<< short(c2) <<" with a size of "<<sizeof(c2)<<endl; cout << char(67)<<endl; cout << "unsigned char"<<short(uc)<<" "<<sizeof(uc)<<endl; //casting cout << "bool size "<<sizeof(b)<<endl; cout << "bool b2 "<<b2<<" b "<<b<<endl; return 0; }https://robark.gitlab.io/basics/iflad/index.htmlThu, 06 May 2021 22:00:24 +0000https://robark.gitlab.io/basics/iflad/index.htmlIf ladders, arrays, data conversion if ladder, auto, bool #include <iostream> using namespace std; int main(){ int x; x=1; int y=2; int z(3); auto a=81; //infers that a is an int auto b=3.14; //b double auto c("Hello"); //c string auto d='A'; // d char //bool e(true); //bool f(false); cout<< x<<y<<z<<a<<b<<c<<d; if (a<9) { cout<<"en"; cout<<"o"; } else if (d=='A') { cout<<"d is A"; } else { cout<<"a is not less than 9"; } return 0; } C arrays and strings #include <cstring> #include <iostream> using namespace std; int main(){ char x[4]; /* x[0]='a'; x[1]='b'; x[2]='c'; x[3]='\0'; //null char null terminated c-string */ strncpy(x, "abcaaaaaaaaaaaaaaaaaaaa", sizeof(x)-1); //string s("abc"); //cout<<s; cout<<x<<endl; //C style printf("the string %s has %i chars \n", x, strlen(x)); return 0; } Data conversion //example convert string -> int string age("14"); //string age="14"; cout<< atoi(age.c_str())+1 << endl; //age.c_str() convert c++ to c string // or if using C++11 cout << stoi(age) << endl; //example convert int -> string int num(14); stringstream ss; ss << num; cout << ss.str() << endl; //or if using C++11 cout << to_string(num)+"hi" << endl; //example of c-string -> double char n[32]; strncpy(n,"12",32); cout<<strtod(n, NULL)+1; //example of c++ string -> double string nn("12.03"); cout<<endl<<strtod(nn.c_str(), NULL)+1;https://robark.gitlab.io/basics/loops/index.htmlMon, 10 May 2021 19:15:16 +0000https://robark.gitlab.io/basics/loops/index.htmlWhile and for loops Integer array loops #include <iostream> using namespace std; int main(){ int a[4] = {11,22,33,44}; //initialization list for (int x =0; x < 4; x++) cout << a[x] << endl; for (auto x: a) cout << x << endl; return 0; } C string array loops #include <cstring> //for strlen #include <iostream> using namespace std; int main(){ char s[12]="Hello World"; cout << s << endl; for (int x =0; x < strlen(s); x++) cout << s[x]; cout << endl; for (auto x: s) cout << x ; cout << endl; return 0; }https://robark.gitlab.io/basics/functions/index.htmlTue, 11 May 2021 17:35:38 +0000https://robark.gitlab.io/basics/functions/index.htmlFunctions: pass by value, pass by reference, default arguments, global variables, static variables Global variables #include <iostream> using namespace std; int g=0; //global var declared outside any function void foo(){ int g=1; cout<<"global g "<<::g<<endl; // 0 :: scope resolution operator cout<<"local g "<<g<<endl; // 1 } void boo(){ cout<<g<<endl; // 0 global } int main(){ foo(); boo(); cout<<"in main "<<g<<endl; // 0 global return 0; } Static Variables