The document outlines a JavaScript training agenda, focusing on data types, operators, and memory management. It provides examples of primitive data types, object creation, and the use of variables within functions and the global window context. The document emphasizes understanding variable assignments, object properties, and type checking in JavaScript.

1. JavaScript Training
Goal Trainers Format
• Lecture
• Exercises
• Ask Questions!
• bitovi/js-training

2. Data Types, Operators and Primitives

3. Undefined undefined
Null null
Boolean true
String "hello"
Number 2
Object {name: "value"}
Array [1,2,3]
Date new Date()
RegExp /.*/g,
Function function(){}
Data Types
Primitive
Object

4. var
new
assignment
delete
member
call
comparison
Operators
var foo
new Foo
foo = {bar: "a value"}
foo.bar = value
delete foo.bar
foo.bar
foo["bar"]
bar()
foo.bar()
==
===

5. var me = {
name: {first: "justin"}
},
name = me.name;
name = {first: "alexis"};
me.name.first // justin

6. WINDOW
Address Value
…. ….
x1001
x1002
x1003
x1004
…. ….
x2001
x2002
x2003
x2004
var str = "hi";

7. var str = "hi";
Address Value
…. ….
x1001 call-object
x1002
x1003
x1004
…. ….
x2001
x2002
x2003
x2004
WINDOW
"hi"

8. Address Value
…. ….
x1001 call-object
x1002
x1003
x1004
…. ….
x2001 STRING
x2002 2
x2003 hi
x2004
"hi"
WINDOW
var str = "hi";

9. Address Value
…. ….
x1001 call-object
x1002
x1003
x1004
…. ….
x2001 STRING
x2002 2
x2003 hi
x2004
str "hi"
WINDOW
var str = "hi";

10. "hi"str
Address Value
…. ….
x1001 call-object
x1002 str
x1003 -----
x1004
…. ….
x2001 STRING
x2002 2
x2003 hi
x2004
WINDOW
var str = "hi";

11. var str = "hi";
Address Value
…. ….
x1001 call-object
x1002 str
x1003 2001
x1004
…. ….
x2001 STRING
x2002 2
x2003 hi
x2004
"hi"str
WINDOW

12. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001
x1002
x1003
…. ….
x2001
x2002
x2003
x2004
…. ….
x2101
x2102
x2103
WINDOW

13. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001 call-object
x1002
x1003
…. ….
x2001
x2002
x2003
x2004
…. ….
x2101
x2102
x2103
WINDOW

14. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001 call-object
x1002
x1003
…. ….
x2001 OBJECT
x2002 0
x2003
x2004
…. ….
x2101
x2102
x2103
WINDOW

15. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001 call-object
x1002 obj
x1003 -----
…. ….
x2001 OBJECT
x2002 0
x2003
x2004
…. ….
x2101
x2102
x2103
obj
WINDOW

16. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001 call-object
x1002 obj
x1003 -----
…. ….
x2001 OBJECT
x2002 0
x2003
x2004
…. ….
x2101
x2102
x2103
obj
WINDOW

17. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001 call-object
x1002 obj
x1003 x2001
…. ….
x2001 OBJECT
x2002 0
x2003
x2004
…. ….
x2101
x2102
x2103
"hi"
obj
WINDOW

18. var obj = {};
obj.txt = "hi";
Address Value
…. ….
x1001 call-object
x1002 obj
x1003 x2001
…. ….
x2001 OBJECT
x2002 0
x2003
x2004
…. ….
x2101 STRING
x2102 2
x2103 hi
"hi"
obj
txt
WINDOW

19. var obj = {};
obj.txt = "hi";
"hi"
obj
txt
Address Value
…. ….
x1001 call-object
x1002 obj
x1003 x2001
…. ….
x2001 OBJECT
x2002 1
x2003 txt
x2004 x2101
…. ….
x2101 STRING
x2102 2
x2103 hi
WINDOW

20. delete
var me ={
name: {
first:"justin"
}
},
name = me.name;
delete me.name;
name.first //-> "Justin"
WINDOW
name
name
"justin"
me
first

21. typeof
Type Result
Undefined "undefined"
Null "object"
Boolean "boolean"
Number "number"
NaN "number"
String "string"
Function "function"
Array "object"
Any other object "object"

22. Summary
Variables are put in a call object.
var me;
= sets a variable or property to
point somewhere in memory.
me = {};
me.age = 30;
WINDOW
me
30
age

23. var me ={
name: {
first:"justin"
}
},
name = me.name;
name = {
first:"alexis"
};
me.name.first
Understanding
WINDOW
name
"alexis"
first
name
"justin"
me
first

24. var me ={
name: {
first:"justin"
}
},
name = me.name;
name = {
first:"alexis"
};
me.name.first
Understanding
WINDOW
name
"alexis"
first
name
"justin"
me
first