Top Pascal Interview Questions
1) Explain what is Pascal?
Pascal is a procedural programming language which supports data structures and structured programming.
2) Define what is Pascal sets?
Pascal set is a collection of elements of the same type. It allows defining the set data type. The set elements are enclosed in a square elements.
3) Explain what is Pascal units?
A Pascal program consists of modules referred as units. A module or unit might consist of some code blocks, which again consist of variables and type declarations, statement procedures, etc. There are many built in units in Pascal.
4) Explain what are the data types included in Pascal?
• Integers: It includes whole number, which allows numbers to be written without any decimals
• Real Numbers: Numbers with decimal or without decimals
• Boolean Data Types: Check the condition true or false
• Char Data Type: With the ordered character set it allows a single character to be written
5) Mention what are the different pointer types used in Pascal?
The different pointer types used in Pascal are
• Record Pointer: It allows the recording of the node and the sub-fields that are used
• Reference Pointer: Pointers are the reference to the dynamically created variables
• Associate Pointer: They have an associated data type with them that they can check for compatibility with another type
6) Mention what are the REPORT method for which the portability is given in Pascal?
The portability given for the Report methods are:
• Application: It consists of the guidelines which allow to use implementation and features according to the compiler, to make the application more portable.
• Compiler: Implemented the language that is likely to implement the features like determining of the types that are compatible with one another.
7) Explain what is Pascal constants?
During program execution, constant is something that remains unchanged.
Pascal allows only following constants to be declared
• Ordinal Types
• Set Types
• Pointer Types
• Real Types
• Char
• String
8) Mention what is the syntax to declare constants?
To declare constants the syntax used is
Const
Identifier = constant_value;
9) Explain how you can define a string?
In different ways, string can be defined
• Character Arrays
• String Variables
• Short Strings
• Null Terminated Strings
• Ansi Strings
10) Explain how file is handled in Pascal?
In Pascal, a file is a sequence of components, and file is determined by the type of the components.
type
file-name = file of base-type;
The base type determines the type of the component. It could be anything like Boolean, subrange, integer, record, arrays and so on
11) Explain how you can make EXE files with Turbo Pascal?
To make EXE file with Turbo Pascal,
• Go to compile menu in turbo Pascal
• Select COMPILE TO MEMORY
• Open the menu again
• It will say Compile to disk
• Select compile
It will create the .exe file
12) In Pascal why do standard strings take less space when used in the program?
• Custom string makes it easier for the program not to take more space and run faster. It also takes the input from the user and makes an entry in the table
• The string type can be formed with the optimum length of the command string which is required and present in the code
• Handling process can be created for the string type so that the constant declaration can be used
• According to the requirement string size can be changed, and the string libraries are used to make it easier to code with
13) Explain what is Constructors and Destructors for Pascal Object?
For Pascal object, there are Constructors and Destructors
• Constructors: It is a special type of methods, which are called automatically whenever an object is formed. Just by declaring a method with the keyword you can create a constructor in Pascal. This method is referred as Init
• Destructors: It is a method that is called during the destruction of the object. Destructor method destroy any memory allocation created by constructors.
14) Mention what are the types of Loops in Pascal?
The types of Loops in Pascal are
• Fixed Repetition: It repeats only a fixed number of times
• Pretest: It tests a Boolean expression, then goes into a loop if TRUE
• Posttest: It executes the loop, then tests the Boolean expression
15) Explain why are semicolons used as statement separators used in Pascal?
• Semi-colon is used as a statement terminator so that other statements can be executed
• There is no semicolon required before the keyword end as it determines the record type declaration
• There is no need of semi-colon for a block or a case statement as it needs to be carried on and gets executed
• For the sequence of statement that is written in more than one statement the semicolon get applied
16) Explain what is the reason for using UNITS?
There are three reasons to use units in programming
• When you want to use the same code in some other program to do the same job
• For ease of handling, some large programs are split into a smaller section
• If you put code in a unit, it becomes easy to call and use it again