Creates a new File instance from a parent pathname string and a child pathname string. If parent is null then the new File instance is created as if by invoking the. Using Bean Validation. Validating input received from the user to maintain data integrity is an important part of application logic. Validation of data can take place. This is not true for all database implementations. In an Oracle RDBMS for example NULL and the empty string are considered the same thing and therefore 'Fish. Hello, I am curious about what's probably a design consideration made when designing the Java language. When considering these possible attempts at array declarations: version; c++ objective c java c ; version used C++11 gcc 4.8 clang 3.5: gcc 4.2: java 1.7: mono 2.10 (C 4.0) show version $ g++ --version $ gcc --version $ javac. By using NULL you can distinguish between put no data and put empty data. Some more differences: A LENGTH of NULL is NULL, a LENGTH of an empty string is 0. Sometimes while programming in java, we get String which is actually an XML and to process it, we need to convert it to XML Document (org.w3c.dom.Document). If myString is in fact null, then any call to the reference will fail with a Null Pointer Exception (NPE). Since java 6, use isEmpty instead of length check (in any. 1 /* 2 * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. You are confusing a null String and the empty String . The two are different. You will of course only get true from that equals( ) call if test is a String .