JavaScript in a Nutshell 2 Authors: Agustin Burgos and me.

1. What JavaScript?
Remove your whats
of JavaScript

2. JavaScript
Simple to use.

3. Good or bad
ECMA

4. Good or bad
JavaScript Dev

5. Be a JavaScript coder
Adapt
Other programming language solution may
not be a solution
Read javascript code, understand it

6. Discovering JS
Practices
Debugging
Libraries

7. Bad
var userResponse = getResponseIfAny(); // Could be false, true or null
if (userResponse != false) {
console.log(“User says yes”)
} else {
console.log(“User says no”)
}
// This does not cover null

8. Bad
var userResponse = getResponseIfAny(); // Could be false, true or null
if (userResponse == true) {
console.log(“User says yes”)
} else if (userResponse != null) {
console.log(“User says no”) // This won’t never get printed
} else {
console.log(“User did not give a response”)
}

9. Bad
var userResponse = getResponseIfAny(); // Could be false, true or null
if (userResponse === null) {
console.log(“User did not give a response”)
} else if (userResponse == true) { // Works but is not good enough
console.log(“User says yes”)
} else {
console.log(“User says no”)
}

10. Good
var userResponse = getResponseIfAny(); // Could be false, true or null
if (userResponse === null) {
console.log(“User did not give a response”)
} else if (userResponse) { // Awesome!
console.log(“User says yes”)
} else {
console.log(“User says no”)
}

11. Bad
var userResponse = getResponse(); // Could be false or true
if (userResponse == true) {
console.log(“User says yes”)
} else {
console.log(“User says no”)
}
// This does work but is shity javascript

12. Good
var userResponse = getResponse(); // Could be false or true
if (userResponse) {
console.log(“User says yes”)
} else {
console.log(“User says no”)
}
// Cool javascript

13. Discovering JS
Practices
Debugging
Libraries

14. Debugging
Use the console
It will almost always be right
Use the debugger from the browser
Chromium tools will always be your friend
Pay attention to exclamation signs and colors

15. Debugging
Dear Firefox.

17. Debugging
Chrome in the other hand.

20. Debugging
Using debugger keyword

22. Debugging
Add watches

24. Debugging
Dear Firefox

25. Debugging
Chrome for the win

26. Debugging

27. Debugging

28. Debugging
On our side
Chrome Dev Tools

29. Debugging
Pay attention to symbols in the console!

30. Debugging
First, everything normal so far.

31. Debugging
Then WAT¿

32. Debugging
Colors are important too!

33. Debugging

34. JavaScript frameworks

35. Discovering JS
Practices
Debugging
Libraries

36. Libraries
External forces are on our side too.
Things like lodash underscore and such make common
functionality ready for use.

37. Libraries
Lodash

38. Libraries
Moment

39. Libraries
jQuery

40. Libraries
jQuery is NOT a Framework

41. Libraries
jQuery is NOT a Framework

42. Libraries
jQuery is NOT a Framework

43. Libraries
jQuery is NOT a Framework

44. Libraries
jQuery is NOT a Framework

45. Libraries
jQuery is NOT a Framework

46. Libraries
jQuery is NOT a Framework

47. Libraries
jQuery is NOT a Framework

48. Libraries
jQuery is NOT a Framework

49. Fin.

50. Libraries
jQuery is NOT a Framework