salesforce - Amount change on Opportunity Apex Trigger [Resolved] -

trigger change quantity in negative number opportunitylineitems final opportunity amount in negative number if record type of opportunity 'revenue risk'

trigger risk_negativequantity on opportunitylineitem (before insert)  {     if(trigger.isinsert)     {       set<id> oppid = new set<id>();       (opportunitylineitem  oli : trigger.new)       {            oppid.add(oli.opportunityid);       }       id revenuerisk= schema.sobjecttype.opportunity.getrecordtypeinfosbyname().get('revenue risk').getrecordtypeid();       list<opportunity> opplist = [select id, recordtype.name,recordtypeid opportunity id in : oppid ];       (opportunitylineitem  oli : trigger.new)       {               (opportunity opp: opplist)           {               if (oli.opportunityid == opp.id)               {                   if(opp.recordtype.name == 'revenue risk')                   {                       if(oli.quantity > 0)                       {                          oli.quantity = oli.quantity * -1;                       }                   }               }           }       }     } } 

the error clear:

if(opplist.amount >= '0'){ // line throw error: 'comparison arguments must compatible types: integer (or double), string       opplist.amount = opplist.amount * '-1'; // 1 too: 'arithmetic expressions must use numeric arguments'  } 

your second code snippet wrong (same first one).

if(opplist.amount >= 0){              opplist.amount = opplist.amount*-1;             // must each.amount = each.amount * - 1; please try not use reserved words variable names         } 

you may want take @ previous post describing typed programming languages: strongly typed