Difference between casting to String and String.valueOf
casting, java
Solution
Casting to string only works when the object actually is a string:
Object reallyAString = "foo";
String str = (String) reallyAString; // works.
It won't work when the object is something else:
Object notAString = new Integer(42);
String str = (String) notAString; // will throw a ClassCastException
`String.valueOf()` however will try to convert whatever you pass into it to a `String`. It handles both primitives (`42`) and objects (`new Integer(42)`, using that object's `toString()`):
String str;
str = String.valueOf(new Integer(42)); // str will hold "42"
str = String.valueOf("foo"); // str will hold "foo"
Object nullValue = null;
str = String.valueOf(nullValue); // str will hold "null"
Note especially the last example: passing `null` to `String.valueOf()` will return the string `"null"`.
Problem
What is the difference between ``` Object foo = "something"; String bar = String.valueOf(foo); ``` and ``` Object foo = "something"; String bar = (String) foo; ```