Syntax for lab exercise 1

Key syntax elements for lab exercise 1

The C++ syntax we will focus on for lab exercise 1 includes:

the use of single-line comments with //

// anything to the right of // (on the same line) is a comment,
//    and is ignored by the compiler

the basic structure of a C++ program

// include any libraries needed, e.g.
#include <iostream>
#include <string>

// provide the main routine, with any actions to be carried out
//   "inside" the main - i.e. between the { and }
int main()
{
    // most part 1 code will go here:
    //    variable declarations, computation, input/output, etc
}

declaring variables

// variables must be declared inside the main routine (or function) they're used in,
//     like the example below
// either way, you must declare variables before (above)
//     the point where they are first used
//
// For variables you specify the type, name, and optionally an initial value.

int main()
{
   // user supplied item name (as text) and weight (in kilos)
   string itemName;
   double itemWeight;

   // ... input and output statements will go here ...
}

output using std::cout, with std::endl for the newline
(output statements are always inside the main routine or a function)

   // print the text Hello there! followed by a newline
   cout << "Hello there!" << std::endl;

   // print the current contents of a variable, e.g. itemName
   std::cout << itemName;

   // print text, a variable, and a newline in a single cout statement
   std::cout << "The name of the item is " << itemName << std::endl;

input using std::cin
(input statements are always inside the main routine or a function)

   // use cout to ask the user to enter the desired value
   std::cout << "Enter the weight of the item in kilograms, e.g. 5.7" << std::endl;

   // then use cin to read the value they enter and put it into a variable
   // (the variable must have been declared earlier in the main routine or function)
   std::cin >> itemWeight;