JavaScript/Notes/Debugging: Difference between revisions

From Noisebridge
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
== It Doesn't Work! ==
* Make sure you've correctly added a closing </SCRIPT> tag.
* Check the error console.
* Validate the HTML Markup
* See also [http://jsfaq.org/notes/code-guidelines/ Code Guidelines for Rich Internet Application Development]
== How to Launch the Debugger ==
A few approaches:
A few approaches:
=== debugger keyword ===
=== debugger keyword ===

Revision as of 17:25, 30 December 2013

It Doesn't Work!

How to Launch the Debugger

A few approaches:

debugger keyword

<source lang="javascript"> function myFunc(myParam) {

 debugger;
 var myVar = 1;
 
 function innerFunc() {
 
 }

} </source>


debugger from the menu

Error creating thumbnail: Unable to save thumbnail to destination

Add a Breakpoint

Error creating thumbnail: Unable to save thumbnail to destination


Debugger Keyword Full Example

Copy'n'paste this example into your text editor, open your browser, and open this file. <source lang="html5"> <!doctype html> <head> <title>Debugger Example</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body>

Test Debugger

When Entering an Execution Context, the Variable Environment is initialized with parameter variables, Function Declarations, and Variable Statements.

function myFunc(myParam) {
  debugger;
  var myVar = 1;
  
  function innerFunc() {
  
  }
}

<script> function myFunc(myParam) {

 debugger;
 var myVar = 1;
 
 function innerFunc() {
 
 }

} </script>

Open the debugger and then click the button below.

<button onclick="myFunc(7)">myFunc(7)</button> </body> </html> </source>