TURBO PASCAL TUTORIAL

Variable Definitions.


integer -  a number that does not have a decimal part. 12 is an integer.

real -  a number which has a decimal part.  3.25 would be a real.

string - a section of text. "Hello world!" would be a string.

char -  one part of a string.  "G" is a character, while "GG" is not.



Example

Var
	age : integer;
	answer : real;
	name : string;



Assigning Variables

We use the := to assign a value to a variable.

Examples of that would be:

  world_stmt := 'Hello world.';   { a definition of a string.  The
                                   ' s must be there on each side }
  choice_char := 'a';             { a definition of a character The
                                   ' s must be there on each side }
  money := 3.25;                  { a definition of a real number}
  coins := 10;                    { a definition of an integer }


                                                                  
Arithmetic computations.

We often have to do arithmetic to program and solve a problem. 

x := 3 + 2;   { we're telling the computer to add 3 and 2 and then
               place 5 in an integer called x.}

y := 10 - 7;   { we're telling the computer to subtract 7 from 10
                and then place 3 in an integer called y. }

z := 3 * 2;     { we're telling the computer to multiply 3 by 2. }

a := 10 / 2;    {dividing 10 by 2 }

Any of these can be combined in one statement, with the order of operations 
being brackets first, then division, multiplication, subtraction and then +. 

For example:

       answer := 3 + (2 + 3) * 4;		{answer would be equal to 23}




Sample Program

program assign1;

uses WinCrt;

var

number1, number2: integer;
result: integer;

begin

number1 := 3;			 {assign first number the value of 3}
number2 := number1 * 2;	        {assign 2nd number-multiply first number by 2}
number1 := number2 - 5;     	{assign 1st number-old value of 1st number - 5}
result := number1 + number2;	{assign result to be 1st number + 2nd number}

end.


Read this to find out what the value of all the variables would be at the end of
the code. The first statement is a simple assign statement,
assigning first number the value of 3.  The second statement assigns second 
number the value of first number (3) * 2 which is 6.  The third statement
then assigns the first number the value of second number (6) - 5 which is
1.  And then the final statement assigns result to the addition of first and
second number.  So, the values of all the variables would be
first number := 1; second number := 6; and result := 7;.




Assignment

Modify the program shown above so that when it is run, it explains what 
you have done and gives the result in user friendly output