Computer Programming with GNU Smalltalk - Free

Appendix C: Answers of Review Questions
Chapter 1
Answers of Review Questions 89
1. Because of the hardware design, computers can only understand two states. We represent this two
states with digits 0 and 1. Combinations of zeros and ones generate some commands that computer
hardware understands. We call these command groups which provide a communication between us
and computer hardware as programming language.
We need them to communicate with computer hardware, because computer hardware can
understand only two states and the programming language we use is eventually translated into the
sum of combinations of this two states which is called machine language.
2. Programs written in a compiled language should be translated into machine language by other
programs called compiler before the execution by the user.
Programs written in an interpreted language is converted to machine code during the execution time
by other programs called interpreter. They do not need a compilation process before they can be
executed by the user but they are a little bit slower than compiled machines, though this is mostly
not a problem anymore for modern computers and for not-so-performance sensitive projects.
Although Smalltalk is designed as a language which uses a virtual machine to work, GNU Smalltalk
acts more like an interpreted language.
3. A programming paradigm is how a programming language looks at the problems to be solved.
4. Yes. Such programming languages are called multi-paradigm programming languages.
No, GNU Smalltalk allows programmers to use only object-oriented programming paradigm.
5. From decimal to binary:
So the answer is: 1000011111
From decimal to octal:
543/2=271 remainder 1
271/2=135 remainder 1
135/2=67 remainder 1
67/2=33 remainder 1
33/2=16 remainder 1
16/2=8 remainder 0
8/2=4 remainder 0
4/2=2 remainder 0
2/2=1 remainder 0