The document discusses programming languages and their evolution. It begins by explaining that a programming language allows communication between humans and computers by telling computers what tasks to perform. It then summarizes the main types of programming languages: 1) Machine language uses binary and is directly understood by computers but is difficult for humans. 2) Assembly language uses mnemonics to make machine language more readable for programmers. 3) High-level languages use words and concepts familiar to humans, making programming accessible to non-experts. However, programs must be translated before computers can execute them. 4) Fourth generation languages provide even more human-friendly features like built-in database support.

1. A Programming Language is a means of communication used to
communicate between people and the Computer. With help of a
Programming Language , a Programmer tells a computer what he
wants to do.
A vocabulary and set of grammatical rules for instructing a
computer to perform specific tasks.
Programming Language

2. 1. Machine Language:-
Machine language is the fundamental language of a computer and is normally
written as string of binary 1s and 0s.Machine Language is native language of
computer that computer understand with out translation
An instruction prepared in any machine language has a two part format. The
first part is the command or operation, and it tells computer what function to
perform. Every Computer has an operation code(opcode) for each of its
function. The Second part of operation is operand, and it tells the computer
where to find and store the data or other instruction that are to be manipulated.
Programming Language Types

3. Advantage of Machine Languages
1. Machine language requires less memory space than other
languages.
2. Machine Language execute very fast by the compute. This is
mainly because machine instruction are directly understood by
the CPU and no translation of the program is required.
Programming Language Types

4. Limitation/Disadvantages of Machine Languages
i. The programs in machine language are not portable across
machines unless the processors are the same as the language
is machine dependent.
ii. Programming in machine language is laborious and tedious as
it requires keeping track of memory locations, operation
codes, state of execution of commands, intermediate results,
etc.
Programming Language Types

5. Limitation/Disadvantages of Machine Languages
iii. Programming in machine language is error prone as it taxes programmer's
memory so much and limits his ability to think logically through the coding.
iv. It is very difficult to locate and debug errors in machine language. The machine
language programmer has to remember all the operation codes, what each code
does and how it affects various registers of the processor.
v. Besides he has to keep track of all the operands and know exactly where they
are stored in memory. vi. It requires deep knowledge of the internal structure of
the computer and hence only computer experts can program a computer in
machine language.
vi. It requires deep knowledge of the internal structure of the computer and hence
only computer experts can program a computer in machine language.
Programming Language Types

6. 2. Assembly Language
To overcome the problems of programming in machine code mnemonics were
introduced. These mnemonics are just memory aids as these abbreviated
words are easy to remember than a series of digits. Thus the first step in the
evolution of programming language was the development of assembly
language. In this language, mnemonics, which are usually two to four letter
words, are used in place of operation codes in machine language and strings of
characters to indicate addresses of location. This language is designed to
replace each machine instruction with a human understandable mnemonics
(such as MUL for multiply, DIY for divide and SUB for subtract, etc. and each
address with an alphanumeric string.
Programming Language Types

7. Advantages of Assembly Language
i. Assembly language is easier to understand and use than _ machine language as it
employs easy to understand symbols in place of numeric codes .
ii. It is easier to locate and correct errors in assembly language. Fewer errors occur
while coding and these errors can be more easily removed.
iii. The program in assembly language can be more easily modified which is very
difficult in machine language. Recording of the logic is preferred to modifying a
program in machine language in case of errors.
iv. Greater flexibility in writing programs in assembly language matching the
computer as all the details of the processor are available to the programmer.
Programming Language Types

8. Disadvantages
i. It is machine dependent. The programs are not portable across
machines as each program is written keeping in mind the
specific design features of the machine.
ii. Programming in assembly language is difficult. It requires
expert knowledge of the internal structure of the processor
and the assembly language programming techniques.
iii. Assembly language programming is time consuming.
Programming Language Types

9. 3. High Level Language
It was realised that the enormous potential of computer could be
realised only if a non-expert user can effectively use the computer for
problem solving. This necessitated the development of high-level
language. The focus shifted from machine-oriented language to
problem-oriented language. Such problem-oriented languages enable a
programmer to write appropriate algorithms to solve problems in
natural languages like English. The two-part machine instruction in
numbers was thus replaced by notation systems made up of natural
language words. Such notation systems used to represent algorithms are
called high level languages.
Programming Language Types

10. Advantages of High Level Languages
i. It is easy to learn and use. High-level language is easy to learn and use as it is close to a familiar
language like English.
ii. Better documentation. High-level language to a large extent is self-documenting, as it is more like
the language of the problem.
iii. Portability. Programs written in high level language are portable across machines, as the language is
machine-independent.
iv. Programming efficiency. Programmer productivity is very high as the programmer can code several
times more lines of program than in any other language.
v. Improved debugging facility. Error detection and removal is easier in high-level language as the
program is easily readable and only logical errors need be checked. Syntax errors are detected and
displayed by the compiler for correction.
vi. Fewer errors. Since the programmer is not required to remember all the small steps to be carried out
by the machine, fewer errors are likely to be there in the code.
vii. Programs in high-level languages are easier to maintain than those in the low-level languages.
Programming Language Types

11. Disadvantages of High Level Languages
i. Lower efficiency. The machine takes more time and main memory to run
a program in high-level language. The object program tends to be less
efficient in terms of storage utilization and running time.
ii. Less flexibility. The high level language is less flexible than machine
language as the automatic features of the high level languages always
occur and are not under the control of the programmer. A large number of
rules are to be adhered to in programming.
iii. High-level language requires translation. A translator program
(interpreter or compiler) is required in translating source code into object
code.
Programming Language Types

12. Fourth Generation Languages(4GL)
These languages are considered to be superior to high-level
languages. These are some programming packages with built in
database management facilities etc. that help in defining data,
validating data, designing input and output forms, handling
queries etc. Compared to high-level languages, these languages
require much less coding. ORACLE, INGRES, SYBASE AND
INFORMIX fall in this category.
Programming Language Types

13. • Integrity. This refers to the accuracy of the calculations. It should be clear that all other program enhancements will be meaningless if
the calculations are not carried out correctly. Thus, the integrity of the calculations is an absolute necessity in any computer program.
• Clarity refers to the overall readability of the program, with particular emphasis on its underlying logic. If a program is clearly written,
it should be possible for another programmer to follow the program logic without undue effort. It should also be possible for the original
author to follow his or her own program after being away from the program for an extended period of time. One of the objectives in the
design of C is the development of clear, readable programs through an orderly and disciplined approach to programming.
• Simplicity. The clarity and accuracy of a program are usually enhanced by keeping things as simple as possible, consistent with the
overall program objectives. In fact, it may be desirable to sacrifice a certain amount of computational efficiency in order to maintain a
relatively simple, straightforward program structure.
• Efficiency is concerned with execution speed and efficient memory utilization. These are generally important goals, though they should
not be obtained at the expense of clarity or simplicity. Many complex programs require a tradeoff between these characteristics. In such
situations, experience and common sense are key factors.
• Modularity. Many programs can be broken down into a series of identifiable subtasks. It is good programming practice to implement
each of these subtasks as a separate program module. In C, such modules are written as functions. The use of a modular programming
structure enhances the accuracy and clarity of a program, and it facilitates future program alterations.
• Generality. Usually we will want a program to be as general as possible, within reasonable limits. For example, we may design a
program to read in the values of certain key parameters rather than placing fixed values into the program. As a rule, a considerable
amount of generality can be obtained with very little additional programming effort.
DESIRABLE PROGRAM CHARACTERISTICS

14. Translator is a System Program that convert the program from one
language to another language. There are different types of
translators:
1. Interpreter
2. Assembler
3. Compiler
Translator/language processor

15. 1. Interpreter
Interpreter is translator used for translating the high level program into
machine code. It takes one statement of a high level language program
and translates it into a machine instruction, which is immediately
executed. Translation and execution alternate from each statement
encountered in the high level language program. In other words, an
interpreter translate one instruction, and the control unit executes the
machine code, the next instruction is translated, and control unit
executes the machine code instruction code, and so on. In case of
interpreter, no object code is save for future use.
Translator/language processor

16. 2. Assembler
An assembler is a program that accepts as input an assembly
language program-and produces its machine language equivalent
Translator/language processor

17. 3. Compiler: A compiler is a program that translates a source
program written in some high level Programming language
into machine code . As an important of this translation
process, the compiler reports to its user the presence of error
in the source program In case of Compiler, object code is save
for future use. It takes all statements of a high level language
program and translates it into a machine instruction
Translator/language processor
High Level
Language
Compiler Machine Code
Error Messages