Ten Groovy Little JavaScript Tips

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Ten Groovy Little
JavaScript Tips
So Cal Code Camp, July 28, 2013
Thursday, July 25, 13

Who am I?
Hi, I’m Troy. I have been developing software for over 30
years. For the last 10 years I have been focused on we...

The Rock n Coder
• http://therockncoder.blogspot.com
• http://www.youtube.com/user/rockncoder
• https://github.com/Rocknco...

Please RateThisTalk
http://spkr8.com/t/22971
Thursday, July 25, 13

The Browser Wars
• ActionScript
• Java
• JavaScript
• JScript
• VBScript
Thursday, July 25, 13

The browser wars are over.
Thursday, July 25, 13

JavaScript won.
Thursday, July 25, 13

Get used to it.
Thursday, July 25, 13

Get better at it.
Thursday, July 25, 13

Our Goal
To provide you with some simple to follow, easy to
remember tips, which can improve your JavaScript.
Thursday, Ju...

The Tips
• Code
• Conditionals
• Conversions
• jQuery
Thursday, July 25, 13

Code
Thursday, July 25, 13

Tip #1
Use protection
Thursday, July 25, 13

Use Protection
• The Browser is a very dirty environment
• Protect your code by wrapping it in a
function
/* using protect...

Tip #2
debugger is your friend
Thursday, July 25, 13

debugger is your friend
• At times it can be difﬁcult to set a
breakpoint
• The debugger statement allows you to set
a bre...

Conditionals
Thursday, July 25, 13

Tip #3
Always Use ===
Thursday, July 25, 13

Always Use ===
• Double equals (==) does automatic type
conversion
• The results of this conversion is not logical
or obvi...

Tip #4
Learn to love falsey
Thursday, July 25, 13

Learn to Love Falsey
• When coming from C# or Java it is
tempting to use C-like conditionals
• JavaScript conditionals can...

Falsey
Type Results
Null FALSE
Undeﬁned FALSE
Number if 0 or NaN, FALSE
String if length = 0, FALSE
Object TRUE
Thursday, ...

Conversions
Thursday, July 25, 13

JavaScript’s Conversion
Shortcuts
• DefaultValue
• To Binary
• To Number
• To String
Thursday, July 25, 13

Tip #5
Getting default value
Thursday, July 25, 13

Getting a default value
• At times it is nice to have a default value
• JavaScript has a kind of default value operator
/*...

Tip #6
Convert to boolean
Thursday, July 25, 13

To Binary
• Double exclamation (!!) converts a value to
its boolean representation (true/false)
/* convert to boolean */
v...

Tip #7
Convert string to
number
Thursday, July 25, 13

To Number
• The plus sign (+) before a numeric string
converts it to a numeric value
/* convert to number */
var toNumber ...

Tip #8
Convert value to string
Thursday, July 25, 13

To String
• Add an empty string (“”) to a value
converts it to a string
var toString = 42 + "";
console.log(toString);
Thu...

jQuery
Thursday, July 25, 13

Thursday, July 25, 13

Tip #9
jQuery isn’t always the
answer
Thursday, July 25, 13

jQuery Isn’t Always the
Answer
• For many tasks plain JavaScript is better
than jQuery
• For example, ﬁnding an element by...

Tip #10
Cache Selectors
Thursday, July 25, 13

Cache Selectors
• jQuery Selectors are method calls, not
operators
• The method calls interrogate the DOM
• Method calls a...

Cache Selectors
/*
jQuery Demo
*/
RocknCoder.plugInSlow = function() {
var i, val;
for(i=0; i < 50; i++) {
val = $('#style...

Bonus Tip #1
Use
event.preventDefault
Thursday, July 25, 13

Use
event.preventDefault
• If your code completely handles an event,
you should be sure to event.preventDefault
• This wil...

Summary
• JavaScript is the most important language of
web development
• But it is a quirky language
• Use these tips to s...

Please RateThisTalk
http://spkr8.com/t/22971
Thursday, July 25, 13

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