check int is null or empty java code example

Example 1: check if string is null or empty java

if(str != null && !str.isEmpty()) { /* do your stuffs here */ }

Example 2: java check if int is null

An int is not null, it may be 0 if not initialized.

If you want an integer to be able to be null, you need to use Integer instead of int.

Integer id;
String name;

public Integer getId() { return id; }
Besides the statement if(person.equals(null)) can't be true, because if person is null, then a NullPointerException will be thrown. So the correct expression is if (person == null)