High level Language :
- First high-level programming languages were designed in the 1950s.
- High level Language is Human understandable Language.
- English is Common example of High Level Language.
- High level Language is Internal Machine Code Independent.
- High level Language is Program Oriented Language.
- High level Language is Developed for providing GUI Interface.
As you can see the above diagram, it clearly shows that HLL are more close to human and can be easily programmed as compare to lower level language.In HLL Language and Machine gap is more.
C Programming can be considered as High Level / Low Level -
- In early 70′s , C Programming was considered as High Level language because it was capable of evaluating expressions,parenthesis recursive functions etc.
- Nowadays C may be considered as “Low Level Language” by some programmer because it lacks a large runtime-system (no garbage collection, etc.)
Execution Models of HLL :
1. Interpreted :
- Interpreted languages are read and then executed directly, with no compilation stage.
- Program is read line by line and convert it into machine code, and executes it. [More Info : Interpreter]
2. Compiled :
Languages are transformed into an executable form before running There are two types of compilation:
2.1 Machine code generation
Some compilers compile source code directly into machine code. Machine code is generated by using compiler it is called as “truly compiled” languages.
2.2 Intermediate representations
Language is converted into middle level language and further optimized and reused.
3. Translated :
- A language may be translated into a lower-level programming language for which native code compilers are already widely available.
- The C programming language is a common target for such translators.
Some High Level Languages :