smalltalk

Question 1

what is Smalltalk?

Answer 1

• an object-oriented language
• no standard syntax for declaring methods
• first language packaged with its own IDE
• evolved from Simula 671 (for simulations)

Question 2

model of computation

Answer 2

• all computation done by sending messages to objects
• variables must be declared before use, but no type is given
• everything is an object (no type needed)

Question 3

objects in Smalltalk include:

Answer 3

• variables
• classes
• numbers
• code

Question 4

Smalltalk general syntax:

Answer 4

//idk why it keeps reverting back to this. this is incorrect. object/message/argument { [argument] }

s push: 10
s size

Question 5

Smalltalk class definitions

Answer 5

• can contain instance and class definitions

* common to all instances of the class

Question 6

Smalltalk messages

Answer 6

written to the right of the recipient

Question 7

Smalltalk class instances

Answer 7

• instance definitions are specific to each object

* instance variables are private to that object

Question 8

Smalltalk class methods

Answer 8

primarily used to create new instances

Question 9

unary

Answer 9

a message without an arg

Question 10

keyword

Answer 10

• a message with an arg

* end in a colon and may be made into a sequence

Question 11

expressions

Answer 11

• always evaluated from left to right
• a sequence of expressions is separated by .
• a value is returned using ^

Question 12

precedence

Answer 12

unary, binary, keyword messages, ^

Question 13

misc syntax

Answer 13

"..." is a comment
/.../ is a string
$a is the character a
#a is the symbol a (don't evaluate)
default value for all variables in Smalltalk is nil