How to get all field names in all objects using Apex in Salesforce?

Sample Code:

List < Schema.SObjectType > gd = Schema.getGlobalDescribe().Values();      

Map<String , Schema.SObjectType > globalDescription = Schema.getGlobalDescribe();   

        

for ( Schema.SObjectType f : gd ) {  

  

    Schema.sObjectType objType = globalDescription.get(f.getDescribe().getName() );  

    Schema.DescribeSObjectResult r1 = objType.getDescribe();   

    Map<String , Schema.SObjectField > mapFieldList = r1.fields.getMap();    

  

    for ( Schema.SObjectField field : mapFieldList.values() ) {    

      

        Schema.DescribeFieldResult fieldResult = field.getDescribe();    

  

        if ( fieldResult.isAccessible() ) {    

          

            System.debug('Field Name is ' + objType + '.' + fieldResult.getName() );  

              

        }   

          

    }  

      

}