How to remove all null elements from a ArrayList or String Array?

Question

I try with a loop like that

// ArrayList tourists

for (Tourist t : tourists) {
    if (t != null) {     
        t.setId(idForm); 
    }   
}

Answer 1

Try:

tourists.removeAll(Collections.singleton(null));

Read the Java API. The code will throw java.lang.UnsupportedOperationException for immutable lists (such as created with Arrays.asList); see this answer for more details.