By on

PASCAL PROGRAMMING

 

PROCEDURE IN PASCAL

While coding, the need to reuse a part of the code might arise. It is not a good practice to copy this part again within the program. Instead, PASCAL has components, that is subprograms called procedures and functions for this purpose. These two components are make the program easier to write, debug and enhances readability.

A procedure is a block of code which only runs when it is called. You can pass data, known as parameters, into a procedure. Procedures are used to perform certain actions. Why use procedures? To reuse code: define the code once, and use it many times. Procedures are subprograms that can return a single value or a group of results. Procedures have a set of parameters, value or variable. Value parameters are those which are only passed to the procedure, because otherwise the procedure would not be able to do the task it is said to. Value parameters do not change after the execution of procedures. They are given in the parentheses which comes after the procedure declaration. Variable parameters are those which may affect the execution of the procedure and need to be updated according to this procedure. They are also given in the parentheses after the procedure declaration, however they have a 'var' keyword before them to indicate that they are variable parameters.

 

Syntax to declare a procedure in pascal:

procedure procedureName(arg(s) : datatype1, arg(s) : datatype2 …);

begin

//statements

end;

TIP: Start with the keyword procedure

Program exercises implementing PROCEDURE in Pascal programming

Lab1

//Pascal program to display your details using procedure

program displayDetailsLabEx;

var

name1, name2 : string;

procedure displayDetails( var yourName : string; fullname : string);

begin

yourName := fullname;  //just like we assign a value to result variable

end;

 

begin

//pass values directly

displayDetails(name1, 'dmactutor');

displayDetails(name2, 'www.whitepaceblog.blogspot.com');

 

writeln('Your name is:: ', name1);

writeln('Your blog site is:: ', name2);

end.

 

 

Lab2

//Pascal program to calculate area of rectangle using procedure

program areaRectangleUsingProcedure;

var

answer, len, wid :real;

procedure calculateAreaRec( var area : real; length : real; width : real);

begin

area := length * width;

end;

 

begin

//ask users for input

writeln('Insert Length in cm''s');

readln(len);

writeln('Insert Width in cm''s');

readln(wid);

calculateAreaRec(answer, len, wid);

writeln('The area of rectangle is:: ', answer:0:2);

end.

TIP: Here, the procedure has three parameters, a variable and two values. area is the variable parameter, length and width are the value parameters. In the procedure call, the value of answer is passed to area, although it does not have any significant initial value, and the value of len is passed to length, while wid is passed to width, that is the input from the user. In the procedure, area gets the value length * width. Then, after the procedure has finished execution, the new value of area is passed to answer. Now, answer stores the calculated value and can be output with precision 2.

TIP2: If you separate the parameters with commas and decide to use one datatype, it generate error, saying 'variable identifier expected'

 

Lab3

//Pascal program to calculate area of rectangle using procedure

program areaRectangleUsingProcedure;

var

a1, a2, a3 : real;

procedure calculateAreaRec( var area : real; length : real; width : real);

begin

area := length * width;

end;

 

begin

//pass values directly

calculateAreaRec(a1, 5, 3);

calculateAreaRec(a2, 2.5, 8.13);

calculateAreaRec(a3, 12.9, 10.5);

writeln('The first area of rectangle is:: ', a1:0:2);

writeln('The second area of rectangle is:: ', a2:0:2);

writeln('The third area of rectangle is:: ', a3:0:2);

end.

 

 

Lab4

program lab4;

var

   n1, n2, n3,  min: integer;

procedure findMin(p, q, r: integer; var ans: integer);

//Finds the minimum of the 3 values

 

begin

   if p < q then

      ans:= p

   else

      ans:= q;

  

   if r < ans then

      ans:= r;

end;

 

begin

   writeln(' Insert three numbers: ');

   readln(n1, n2, n3);

  

   //call the procedure

   findMin(n1, n2, n3, min);

  

   writeln(' Minimum: ', min);

end.

OUPTUT

Insert three numbers:

45 20 199

Minimum: 20

 

 

FUNCTION IN PASCAL

Functions are similar to procedures, except that they return one value with a specified type and all its parameters should be input parameters, that is value parameters. That is only one value should be able to be changed.

Syntax to declare a function in Pascal:

function functionName(arg(s) : datatype1, arg(s) : datatype2 …) : datatype;

begin

//statements

end;

TIP: Start with keyword function

 

Program exercises implementing FUNCTION in Pascal programming


Lab5

//Pascal program to display your details using function

program displayDetailsLabEx;

var

fname : string;

function displayDetails(fullname : string) : string;

begin

displayDetails := fullname;

end;

 

//main

begin

 

fname := displayDetails('dmactutor');

writeln('Your Youtube handle is:: ', fname);

end.

 

Lab6

//Pascal program to calculate area of rectangle using function

program areaofRectLabEx;

var

answer, len, wid : real;

function areaRect(length, width:real) : real;

begin

areaRect := length * width;

end;

 

//main

begin

writeln('Insert length in cm''s ');

readln(len);

writeln('Insert width in cm''s ');

readln(wid);

 

answer := areaRect(len,wid);

writeln('The area of Rectangle is:: ', answer:0:2);

end.

Comments

Post a Comment

Popular posts from this blog

By on
Image
   DATA STRUCTURE WITH C++ PROGRAMMING USING STACK PREREQUISITES TO IMPLEMENTING STACK IN C++ We will need to understand how to use some of the constructs in C++ that makes up the implementation of stack in C++ against. And this concepts will also help you in developing other codes and to debug or understand the C++ codes in a company's code bank or to interpret a boiler plate code (a ready made code). Some of these constructs or concepts are: 1. sizeof() 2. Function 3. Pointer 4. Function Pointer 5. Arrow operator 6. malloc() 7. typedef 8. struct PHASE 1: sizeof() It is used to determine the size of variables used in a program, it can determine the size of primitive (or predefined) datatype too and for any user-defined datatypes. It is an inbuilt keyword and a compile-time operator. syntax-1 using variable sizeof(variableName); syntax-2 using primitive datatype sizeof(datatype); //code implementation #include<iostream> using namespace std; int main(){ //declare v...
Read more
By on
Image
 ADDING FILES TO YOUR GITHUB ACCOUNT & Inspect Element & Export SQL file from XAMPP sign into your github account create a new repository give it a name of your choice click create repository ensure you are in the project folder directory for quick access; copy the folder on the desktop open git bash terminal cd desktop cd folder-name (cd whitepace-academy) HANDLE few git commands type:: git init (a git folder is created in your project folder) type:: git add . (add the period sign) type:: git config --global user.email "ajalabamise@gmail.com" type:: git config --global user.name "ajalabamise" type:: git commit -m "initial commit"  (it shows all your folder files) CONNECT your local github folder in your github repository copy and paste the code below from your github repo into your git terminal and press enter key git remote add origin https://github.com/ajalabamise/my-web-dev-tutorial.git UPLOAD the files to github repo git push -u or...
Read more
By on
Image
 CGPA CALCULATOR & BASIC HTML WEB DEV PROJECT Introduction: In this cgpa calculator, user will enter the gp for each semester, then click on the submit button to see the cgpa user can also click the reset button to begin a new input for calculation In this mini project we will be using HTML CSS JAVASCRIPT to develop a cgpa calculator NB:   With a querySelector statement, you can select an element based on a CSS selector. This means you can select elements by ID, class, or any other type of selector. Using the getElementById method, you can only select an element by its ID. Generally, you should opt for the selector that most clearly gets the job done. PHASE 1a:  PROTOTYPE (final product) PHASE 1b:  PROTOTYPE (rought sketch) Let's sketch with our hand how the cgpa calculator will look like PHASE 2: Html (for structuring the webpage content) Shortcut for div and class for css: type dot followed by the name you want e.g .cgpatitle Shortcut for div and id f...
Read more