21 of the best jQuery Syntax Guidelines

Every jQuery programmer should know these basic syntax rules or they will die a horrible keyboard death.

Read carefully and get back to basics!

1. Spacing1: Opening braces are always prefixed by a space.  ie – if ( instead of if(
2. Spacing2: Always have spaces after commas and colons. ie – param, param or var; var
3. Equality: Try to use === instead of == to help with comparisons
4. Comments: Long comments should use /* … */
5. Blocks: if/else/for/while/try always have braces and always go on multiple lines
6. Function Calls: Always include extra spaces around the arguments. ie – foo( true );
7. Null Checks: use === null or === undefined
8. Assignments: Assignments should always have a semicolon after them. ie – var test2 = false;
9. Regular Expressions1: should be done using .test() and .exec(). “string”.match() is no longer used
10. Regular Expressions2: Use regexp to remove blank spaces from a string:
    $(‘#title’).val().replace(/^s+|s+$/g, ”) == ”)
11. Nodes: .nodeName should always be used in favor of .tagName
12. Strings: Strings should always use double-quotes instead of single-quotes
13. Switch: Use switch statements to reduce code and improving performance
14. Chain Selectors: Same time by chaining selectors. ie – $(“.someclass, h3”)
15. First and Last: use :first and :last to dynamically select the first and last elements
16. Even and Odd: use :even and :odd to dynamically select alternate elements
17. Ditch target=_blank: Make all links open in new window $(‘a[href^=”http://”]’)    .attr({ target: “_blank” });
18. Alert(): use alert(“hi”); to help with debugging code
19. Use a cheat sheet: Example cheat sheet
20. Selector Context: give your selectors context. ie – var selectedItem = $(‘#listItem’ + i);
21. IE Controls: Use specific jQuery to fix IE bugs: if ($.browser.msie) {   // Internet Explorer fixes;  }

Source(s):  http://docs.jquery.com/JQuery_Core_Style_Guidelines