A computer language is a means of communication between human being and computer. It is a tool for developing Software. The programmer must understand the syntax (grammatical rule) of the language so that software statement are written to conform to these rules.
A statement constructed from a computer language can be regarded as a command which describes what types of processing to be done. Processing can be in form of arithmetic operation, relational operation, or repetitive operations, etc.
Generations of programming languages
Programming language are classified into generations.
A. First generation language is machine language.
It allows programme statement to be written in binary codes comprising digits ‘0’ and ‘1’s only.The 1s and 0s correspond to on and off electrical states respectively. All data are also represented in binary.
Machine language instruction vary in content and format according to the architecture of the computer in use.
Therefore, machine language programs can only be run on the computer for which they were designed. The language; this means that, its instruction are machine dependent
b. Second generation language
The second generation language is the ” Assembly language “. The assembly language was developed to ease the task of programme writing.
Rather than using long string of binary digits of the machine language, symbolic codes are usef to write programme statement in the assembly language. Each statement of assembly language. The ASSEMBLER translates assembly language programme to the corresponding machine language statement.
Assembly language and machine language are classified as low-level languages as they are both machine-dependent. Assembly language is still in use till today.
It is by professionals who are familiar With the architecture of a computer being used. When storage must be minimized or processing speed should be increased, assembly language is recommended for the use to tailor programme instruction to the computer in use.
Characteristics of the first and second generation languages
1. They are more technical to use
2 . They are flexible
3. They are les users- friendly
4. Processing of programme is faster as a programme written in machine language require no translation before execution and that written in assembly language is directly translated.
C. Third generation language
Third generation language are also known as high-level languages. They are also referred to as procedural or problem-9)oriented language.
High level languages instruction comprise of list of steps, or procedures in form of commands of the particular high-level language in use that tell the computer how to solve a particular problem.
They are machine independent, that is , they are more involved with the development of procedure to solve the problem on hand hence the term procedural or problem-oriented.
High level language are design to run on a number of different computer with few or no chances. Instruction resemble the the normal text of familiar human languages in form of codes and and mathematical formulas.
Popular high-level language are : BASIC (beginners all purpose symbolic instruction code), FORTRAN (formula translation) and COBOL (common business oriented language) . Some other high-level languages are: pascal, Ada, c, Modular-2 ALGOL, Prolog, pl/1, etc.
Each instruction statement of a high-level language is translated to many statement of assembly language or machine language. Two translator for high-level languages are the compiler and the interpreter (discussed earlier).
Characteristics of third-generation language
1.They relieve programmers of the detailed and tedious task of writing programs in machine and assembly language.
2. High level language programs can be used on more than one type of machine with few changes, in other words, they are portable.
3. They are easily learnt, that is, they are less technical.
4. They are more flexible compare to machine and assembly language
5. They are more user-friendly
6. Processing speed is Slower