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C++ for new friends: Difference between revisions
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>Knobbler No edit summary |
>IRIXUser (needs moar tabs, stylistic fixups (CONSISTENCY!), et al) |
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#include <iostream> | #include <iostream> | ||
//int main is where you will be writing your code example | // int main is where you will be writing your code example | ||
//int main(){code goes here} | // int main(){code goes here} | ||
int main() | int main() | ||
{ | { | ||
//std::cout is sending the text to your screen | // std::cout is sending the text to your screen | ||
//std::endl creates a new line | // std::endl creates a new line | ||
std::cout << "This text will appear on your sceen" << std::endl; | // note: 'std::' means you are using a member of the namespace 'std' | ||
std::cout << "This text will appear on your sceen" << std::endl; | // more on that later. | ||
// | std::cout << "This text will appear on your sceen" << std::endl; | ||
std::cout << "This text will appear on your sceen" << std::endl; | |||
// note: all statements must end with a ; such as above | |||
return 0; | return 0; | ||
} | } | ||
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int main() | int main() | ||
{ | { | ||
//Numbers in C can be stored in variables | // Numbers in C (or C++) can be stored in variables | ||
//Each type can store a different type of data | // Each type can store a different type of data | ||
//For example an int is created by typing keyword int followed by a name, for this example bill | // For example an int is created by typing keyword int followed by a name, for this example bill | ||
int bill; //this int can store Integers -3 -2 -1 0 1 2 3 etc | int bill; //this int can store Integers -3 -2 -1 0 1 2 3 etc | ||
bool tom; //can store true or false | bool tom; //can store true or false | ||
float jim; //can store a decimal | float jim; //can store a decimal | ||
char tommy; //this takes characters such as 'x' or 'b' | char tommy; //this takes characters such as 'x' or 'b' | ||
// variables can be created with no data and set later in the program such as here | |||
bill = 5; | |||
tom = true; | |||
jim = 1.5; | |||
tommy = 'b'; | |||
//note tom will appear as 1 or 0 depending on the true/false state | // just to prove everything works we will print these to the screen | ||
std::cout<< "BIL "<<bill<<std::endl; | |||
std::cout<< "TOM "<<tom<<std::endl; | |||
std::cout<< "JIM "<<jim<<std::endl; | |||
std::cout<< "TOMMY "<<tommy<<std::endl; | |||
// note: tom will appear as 1 or 0 depending on the true/false state | |||
return 0; | |||
return 0; | |||
} | } | ||
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{ | { | ||
int bill = 5; | int bill = 5; | ||
char tommy = 'b'; | char tommy = 'b'; | ||
//the if statement will look if the condition inside its brackets is true, | // the if statement will look if the condition inside its brackets is true, | ||
//if it is it will run the block of code below | // if it is it will run the block of code below | ||
//we are using the Equal to operator "==" to check if bill is equal to 5 | // we are using the Equal to operator "==" to check if bill is equal to 5 | ||
// other operators include | |||
// != Not equal to | |||
// > Greater than | |||
// <= Less than or equal to | |||
// >= Greater than or equal to | |||
if(bill == 5) | |||
{ | |||
tommy = 'X'; | |||
// because bill is equal to 5 tommy will become X | |||
} | |||
if(bill == 6) | |||
{ | |||
tommy = 'Y'; | |||
//because bill is not equal to 6 this code is ignored | |||
} | |||
std::cout<< "TOMMY "<<tommy<<std::endl; | |||
return 0; | return 0; | ||
} | } | ||
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int main() | int main() | ||
{ | { | ||
int bill = 5; | |||
char tommy = 'b'; | |||
// like if, the while loop will run code if the condition is true | |||
// unlike if, while loops do not stop until the condition becomes false | |||
// below we used the Not equal to operator to check if bill is not equal to 0 | |||
while (bill != 0) | |||
{ | |||
std::cout<< "TOMMY "<<tommy<<std::endl; | |||
//while bill is not equal to 0 the loop will run and print out tommy | |||
bill--; | |||
//the loop will also reduce bill by 1 each time it runs | |||
//thanks to the decrement operator "bill--" bill could also be Incremented with "bill++" | |||
} | |||
return 0; | |||
return 0; | |||
} | } | ||
Revision as of 21:05, 4 February 2014
It is recommended to use an IDE, for a tutorial on how to set one up click HERE
Other great resource for learning C++ from the ground up.
Printing text to the screen
//Text that starts with "//" is ignored by the compiler //This is the library that allows you to use the "cout" and "endl" objects #include <iostream> // int main is where you will be writing your code example // int main(){code goes here} int main() { // std::cout is sending the text to your screen // std::endl creates a new line // note: 'std::' means you are using a member of the namespace 'std' // more on that later. std::cout << "This text will appear on your sceen" << std::endl; std::cout << "This text will appear on your sceen" << std::endl; // note: all statements must end with a ; such as above return 0; }
Using Data
#include <iostream> int main() { // Numbers in C (or C++) can be stored in variables // Each type can store a different type of data // For example an int is created by typing keyword int followed by a name, for this example bill int bill; //this int can store Integers -3 -2 -1 0 1 2 3 etc bool tom; //can store true or false float jim; //can store a decimal char tommy; //this takes characters such as 'x' or 'b' // variables can be created with no data and set later in the program such as here bill = 5; tom = true; jim = 1.5; tommy = 'b'; // just to prove everything works we will print these to the screen std::cout<< "BIL "<<bill<<std::endl; std::cout<< "TOM "<<tom<<std::endl; std::cout<< "JIM "<<jim<<std::endl; std::cout<< "TOMMY "<<tommy<<std::endl; // note: tom will appear as 1 or 0 depending on the true/false state return 0; }
Conditions
#include <iostream> int main() { int bill = 5; char tommy = 'b'; // the if statement will look if the condition inside its brackets is true, // if it is it will run the block of code below // we are using the Equal to operator "==" to check if bill is equal to 5 // other operators include // != Not equal to // > Greater than // <= Less than or equal to // >= Greater than or equal to if(bill == 5) { tommy = 'X'; // because bill is equal to 5 tommy will become X } if(bill == 6) { tommy = 'Y'; //because bill is not equal to 6 this code is ignored } std::cout<< "TOMMY "<<tommy<<std::endl; return 0; }
Loops
#include <iostream> int main() { int bill = 5; char tommy = 'b'; // like if, the while loop will run code if the condition is true // unlike if, while loops do not stop until the condition becomes false // below we used the Not equal to operator to check if bill is not equal to 0 while (bill != 0) { std::cout<< "TOMMY "<<tommy<<std::endl; //while bill is not equal to 0 the loop will run and print out tommy bill--; //the loop will also reduce bill by 1 each time it runs //thanks to the decrement operator "bill--" bill could also be Incremented with "bill++" } return 0; }