Create Trigger for Checkbox

Scenario:

Assume that you have field as Default( checkbox), If New Record Default  field equal to True update all old records equal to False.

Code:

trigger makenewcheckboxtodefault on Account (before insert) {
    list<Account> acc=[select id,Name,Default__c from Account];
       for(integer i =0; i<acc.size();i++){
          if(acc[i].Default__c==true ){
              acc[i].Default__c=false;
           }
        }
 update acc;
}

Alternative method:

you can write this logic in Apex class and you can call Apex method name in a Trigger.

To readers:If you need any further assistance and if you find any mistakes  let me know

Thanks:)

Create Anything!!! Control Anything!!!