APEX LIB

{!IF(x.A_Type__c = 'abc','this is true','this is false')}


<!-- date format -->
<apex:outputText value="{0,date,MM/dd/yyyy}">
<apex:param value="{!d.Start_Date__c}" />
</apex:outputText>

DateTime myDateTime = system.now();
String method1= myDateTime .format('MM/dd/yyyy');
Sting method2= myDateTime .month()+'/'+myDateTime .day()+'/'+myDateTime .year();


String abc = 'a,b,c';
abc.split('\\,');  //记得就加 \\


http://www.salesforce.com/us/developer/docs/pages/Content/pages_compref_outputText.htm