1. High Level Programming Languages
Basic Concepts

2. Machine Code Issues Have to remember numeric opcodes
Have to think about physical memory locations
Machine code
901 1
307 2
506 3
207 4
902 5
000 6
010 7 8 9

3. Assembly
Assembly Code : human readable machine code

4. Different Representations
English: Assembly: Machine:

5. High Level Languages Languages Generations: High level language
1st : Machine code
2nd : Assembly
3rd : High Level languages
High level language
Abstracts away from details of machine code
Focuses on problem solving
Ex: C++, Java, Python

6. Different Representations
High Level Language: Assembly: Machine:

7. Translation
High level languages need to be translated to machine ones:
Compiler : ahead of time, all at once
Interpreter : on the fly, line by line

8. Different Representations
Machine code is unique to a machine
High level code platform independent
Translate to any machine
Machine Code for Computer 3 …
Machine Code for Computer 2 …
Machine Code for Computer 1 …

9. Language History It all starts with FORTRAN:

10. Syntax
Syntax : Rules for how a language works

11. Syntax
Syntax errors in English can change meaning:

12. Syntax
Syntax errors in code prevent translation: Code will not run

13. Syntax Different languages have different syntax