computer language

    In the computer industry, these abbreviations are widely used to represent major steps or "generations" in the evolution of programming language. 1GL or first-generation language was (and still is) machine language or the level of instructions and data that the processor is actually given to work on (which in conventional computers is a string of 0s and 1s). usually, the formation is a punched tape.

    2GL or second-generation language is assembler (sometimes called "assembly") language. usually, asm for short. A typical 2GL instruction looks like this:

ADD 12,8;

An assembler converts the assembler language statements into machine language.

    3GL or third-generation language is a "high-level" programming language, such as PL/I, C, or Java. Java language statements look like this:

public boolean handleEvent (Event evt) { switch (evt.id) { case Event.ACTION_EVENT: ...}}

A compiler converts the statements of a specific high-level programming language into machine language. (In the case of Java, the output is called bytecode, which is converted into appropriate machine language by a Java virtual machine that runs as part of an operating system platform.) A 3GL language requires a considerable amount of programming knowledge.

    4GL or fourth-generation language is designed to be closer to natural language than a 3GL language. Languages for accessing databases are often described as 4GLs. A 4GL language statement might look like this:

EXTRACT ALL CUSTOMERS WHERE "PREVIOUS PURCHASES" TOTAL MORE THAN $1000

    5GL or fifth-generation language is programming that uses a visual or graphical development interface to create source language that is usually compiled with a 3GL or 4GL language compiler. Microsoft, Borland, IBM, and other companies make 5GL visual programming products for developing applications in Java, for example. Visual programming allows you to easily envision object-oriented programming class hierarchies and drag icons to assemble program components.