Free Pascal Tutorials - Lazarus Program Example Code

Contains the link to download Free Pascal and Lazarus, shows how to make and compile a program.

Simple math calculations are shown in this tutorial.

Variables are used to hold data in memory. The data type tells the computer what type of data the variable will hold.

Up to this point, the examples worked with data that was hard coded into the program. This tutorial works with getting input from the user and placing the input into variables.

If statements are used to make decisions.

A case statement is just like an if statement. The case statement works well for menus.

The computer is excellent for doing things over and over again. This tutorials shows the While Loop.

This tutorial shows examples of the Repeat Until Loop.

This tutorial shows examples of the For Loop.

Sometimes the user does not enter correct information. The programmer must check to see if the information is correct or not.

When the user places not numeric data into a data type, that is expecting a number, the program will crash. The Val function can be used to prevent the program from crashing.

Menus are extremely important for directing the user to control the program’s function and understand what the program is capable of doing.

Randomizing data can be used in games and to calculate mathematical possibilities.

Guess My Number is a classic game that incorporates much of what the previous tutorials covered.

Procedures are used to chop large programs into understandable chunks. Procedures allow the programer to call code without having to write the code again.

Values can passed to procedures.

Functions are just like procedures with the exception that a function can return a value.

Arrays can hold data of the same data type.

Gotoxy places the screen cursor at a location on the screen.

Parallel arrays work together to hold data that is related to the data in the other array(s)

Two arrays will be combined to make a 2D array (matrix)

This tutorial will check each element in the array and find the highest and lowest number.

Sometimes, we do not want duplicate data loaded into the array. This tutorial will show how to prevent duplicate data from being stored in the array.

Strings are an array of characters. This tutorial shows how to call parts of the string and manipulate the data.

A palindrome is a word (string) that is the same backwards and forwards. This tutorial shows how to convert the string so it is backwards, then check the backwards string with the original string to see if the strings are the same.

ASCII codes are used, in Tutorial 26, to separate letters, numbers and other characters from the string.

This tutorial is similar to Tutorial 26 with exception that this tutorial uses ranges to separate letters, numbers and other characters from the string.

TProcess is used to run batch programs, Paint, IE and the calculator.

Records are used to combine variables into one data type.

Placing records into an array prevents the need for using parallel arrays.

This video shows how to make and write to text files.

The text file from Tutorial 31 is read.