Introduction to programming with JavaScript, Chapter 1. Video version: https://www.youtube.com/watch?v=Ps03yn2XlUw In this chapter, we explore the basics of computer programming through hands on exercises with JavaScripts. Concepts covered: - expressions - statements - values - operators

1. chapter 1
communicating with your computer

2. English
French
Spanish
Chinese

3. We talk to computers with
programming languages.
c++

4. JavaScript

6. Chakra V8 SpiderMonkey

7. http://repl.it/languages/JavaScript

8. input output

9. input output
JavaScript Code text, behavior

10. what is 2 + 2?
4!

11. 2 + 2;

12. 2 + 2;
expression

13. 2 + 2;
expression
semicolon ends
the expression

14. 2 + 2;
expression
semicolon ends
the expression
arithmetic operator

15. 2 + 2;
expression
semicolon ends
the expression
arithmetic operator
value value

16. 2 + 2;
evaluates to
the value 4

17. var sum = 2 + 2;

18. var sum = 2 + 2;
expression
assignment operator
identifier
keyword to declare
new variable

19. sum;
evaluates to
the value 4

20. var sum = 2 + 2;
sum = 4 + 10; // sum now equals 14

21. var sum = 2 + 2;
sum = 4 + 10; // sum now equals 14
comment, ignored by the JavaScript engine

22. var sum = 2 + 2;
sum = 4 + 10; // sum now equals 14
sum + 10; // evaluates to 24

23. var sum = 2 + 2;
sum = 4 + 10; // sum now equals 14
sum = sum + 10; // sum equals 24

24. 10 - 6; // evaluates to 4
10 * 4; // evaluates to 40
10 / 2; // evaluates to 5

25. 10 - 6; // evaluates to 4
10 * 4; // evaluates to 40
10 / 2; // evaluates to 5
subtraction operator
multiplication operator
division operator

26. Review

27. What are the values in this expression?
1 + 45 + 10 + 20;

28. What does this expression “evaluate” to?
99 + 1 + 10;

29. What does this expression “evaluate” to?
// 34 + 5 + 1;

30. What value is the variable bottles set to?
var cans = 2 + 10;
var bottles = 2 + cans - 10 - cans;

31. Homework #1
Write a JavaScript
expression which adds
5 to 10.
This expression
should evaluate to 15.
Use www.repl.it to
write your code.

32. Homework #2
Define three variables. One
should hold your age, one
should hold your favorite
number, and one should hold
the number of siblings you
have.
Next, define a new variable
which stores the result of
adding the previous three
variables together.

33. Homework #3
Define a variable to hold the number
of hours in a day.
Multiply this value by 7 to get the
number of hours in a week. Assign
this to a new variable.
Next, multiply this by the number of
weeks in a year (52) and assign the
result of this in a new variable.
Finally, divide this number by the
number of days in a year (365). What is
the result?

34. Intro to Programming
with Seth McLaughlin