# Computing - Programming Languages > Source: https://ollybritton.com/notes/a-level/computing/topics/programming-languages/ · Updated: 2020-09-21 · Tags: computing, school, safe-to-post-online # Programming Languages ##### What is a low level programming language?? A programming language that provides little or no abstraction of a computer's instruction set. ##### What are the two parts of an instruction in machine code?? * The opcode * The operand ##### What is the purpose of having an opcode and an operand?? What do you have (operand) and what do you want do with it (opcode). ##### What is an instruction set?? All the instructions that a computer can understand and exectue. ##### An operand can be either?? * An actual value * An adress in memory to a value ##### What abstraction does assembly language provide for opcodes?? Each opcode is replaced by a mneumonic which gives a clue to the what the operation did. ##### What abstraction does assembly language provide for operands?? You can specify operands as decimal or hexadecimal instead of binary. ##### What is the key similarity between assembly and machine code?? There is a one-to-one correspondence between assembly language and machine code. ##### What does LDA mean?? Load address. ##### What does STO mean?? Store the value. ##### What is the main advantage for assembly instead of machine code?? * Don't have to manually type in 1s and 0s. * Quicker ##### What is the main disadvantage for assembly instead of machine code?? You have to convert the assembly to machine code first. ##### How is assembly converted to machine code?? By an assembler. ##### What was the first high level language?? FORTRAN ##### What is an imperative high-level language?? A programming language that consists of commands for the computer to perform. ##### What is the opposite to an imperative high-level language?? Declarative language. ##### What is the main advantage of a declarative programming language?? You can focus on what the program should do without listing the steps needed to achieve the result. ##### SQL is what type of high-level language?? Declarative. ##### What is the main advantage for a high-level language?? The programmer can think and code in terms of algorithms rather than worrying about the computer will execute each tiny step. ##### What must happen to a high-level language before it can be executed?? It has to be converted to machine code. ##### What is meant by a portable programming language?? A program written for one type of computer can be recompiled for a different type of computer. ##### Why will a high-level language run slower?? Compiled code won't be as fast or optimised as raw assembly or machine code. ##### Why is larger object/machine code a problem for some environments?? In embedded com ##### What's an example of an imperative language?? C++ ##### What's an example of a declerative language?? SQL ##### What are 1st generation programming languages?? Machine code ##### What are 2nd generation programming languages?? Assembly ##### What are 3rd generation programming languages?? Imperative programming languages ##### What are 4th generation programming languages?? Declearive programming languages ##### What are 5th generation programming languages?? Natural language/scratch-live programming languages. ### 2021-07-08 ##### What are three advantages of using a low-level language?? * It's often faster * It often uses less memory * You have better access to hardware --- Olly Britton — https://ollybritton.com. Machine-readable index: https://ollybritton.com/llms.txt