qgis - Create and immediately update field using Field Calculator

You can create fields and once created, populate them with data using the Field Calculator. But can you do both at the same time using an expression? Or must you do it in 2 steps?

Answer

You can open the attribute table, toggle layer editable (if not yet done) open the field calculator and check Create a new field, give it a type / name and use an expression to fill it with values based on existing attributes.