低级语言和高级语言（Low level language and high-level language）.doc

低级语言和高级语言（Low level language and high-level language） 13.3.1 low-level language and high-level language Computer programming languages can be divided into two types: low level language and high-level language. 1. low level language Low-level languages provide the ability to manipulate the underlying hardware of a computer system. A skilled programmer usually uses low-level languages to write bottom system software such as operating systems, device drivers, and compilers. Low-level languages use the CPU instruction set to directly call processors, registers, and memory addresses, and maintain very high efficiency in these operations. Since different CPU provides different instruction sets, low-level languages rely on computers. Low level languages are very flexible and efficient in processing hardware, but writing programs requires a more thorough understanding of operating systems and hardware, usually only by a few professional programmers. (1) machine language A machine language is a programming language that exists in binary form and can be directly executed by a computer. Every sentence in a machine language is a machine instruction consisting of binary operands and operands. Machine language is difficult for people to understand and difficult to master. It is only used in the initial stage of computer development. (2) assembly language Assembly language uses some mnemonic symbols to represent the instructions and data in machine language, and makes the machine language symbolic. Therefore, sometimes assembly language is also called symbolic language. Different types of computer systems usually have different assembly languages. Assembly language before execution, it is necessary to use assembly system to translate assembly language into machine language. As shown in figure 13.9. 2. high-level language The high-level language also provides the instructions or statements needed to write programs, but these statements are very close to human language and are quite