C++Introduction for numerical methods in M.Sc
- 2. 1. Machine level language 2. Assembly language 3. High-level language Classification of computer language
- 3. Machine level language Only language of a computer understand by it without using a translation program. Normally written as strings of binary 1s and 0s
- 4. A typical language instruction format OPCODE tells the computer which operation to perform from the instruction set of the computer OPERAND tells the address of the data on which the operation s to be performed
- 5. Advantage Can be execute very fast Limitations Machine Dependent Difficult to program Error prone Difficult to modify
- 6. Assembly/ symbolic Language Using alphanumeric mnemonic codes instead of numeric codes for the instruction in the instruction set. E.g. using ADD instead of 1110(binary) or 14 (decimal) for instruction to ADD . Allowing storage locations to be represented in the form of alphanumeric addresses instead of numeric addresses e.g. representing memory location 1000,1001 and 1002 as FRST, SCND and ANSR respectively.
- 7. Assembler Software that translates as assembly language program into an equivalent machine language program of a computer. ASSEMBLER INPUT Assembly Language program OUTPUT Machine Language program
- 8. Easier to understand and use. Easier to locate and correct errors. Easy to modify. No worry about addresses. Advantages of Assembly language over Machine language Disadvantages of Assembly language • Machine dependent • Knowledge of hardware required
- 9. Machine independent. Do not require programmers to know anything about the internal structure of computer on which high-level Language programs will be executed High-level language •. Deal with high-level coding, enabling the programmers to write instruction using English words and familiar mathematical symbols and expressions.
- 10. Compiler Translator program (software) that translates a high level language program into its equivalent machine language program. Compiles a set of machine language instructions for every program instruction in a high level language.
- 11. Interpreter Interpreter is a high level translator Takes one statement of a high level language program, translates it into machine language instructions. Immediately executes the resulting machine language instructions Compiler simply translates the entire source program into an object program and is involved in its execution. INTERPRETER INPUT OUTPUT High level Language program Machine Language program
- 12. Advantages Machine independent. Easier to learn and use. Fever errors during program development. Better documentation. Easier to maintain. Limitations •Less flexibility to control the computer’s CPU, memory and registers
- 13. Source Code : $ Source code refers to high level code or assembly code which is generated by human/programmer. $ Source code is easy to read and modify. $ It is written by programmer by using any High-Level Language or Intermediate language which is human-readable. $ Source code contains comments that programmer puts for better understanding. Source code is provided to language translator which converts it into machine understandable code which is called machine code or object code. Computer can not understand direct source code, computer understands machine code and executes it. It is considered as fundamental component of computer. Source code is a set of instructions/commands and statements which is written by a programmer by using a computer programming language like C, C++, Java, Python, Assembly language etc. So, statements written in any programming language is termed as source code
- 14. Object code refers to low level code which is understandable by machine. Object code is generated from source code after going through compiler or other translators. It is in executable machine code format. Object code contains a sequence of machine understandable instructions to which Central Processing Unit understands and executes. Object file contains object code. Some object file examples are common object file format (COFF), COM files and “.exe” files. It is the output of a compiler or other translator. We can understand source code but we can not understand object code Object Code :
- 15. The source code and object code