With a third party API I observed the following.
Instead of using,
public static string getString(){
return "Hello World";
}
it uses something like
public static void getString(String output){
}
and I am getting the "output" string assigned.
I am curious about the reason of implementing such functionality. What are the advantages of using such output parameters?
Something isn't right in your example.
class Foo {
public static void main(String[] args) {
String x = "foo";
getString(x);
System.out.println(x);
}
public static void getString(String output){
output = "Hello World"
}
}
In the above program, the string "foo" will be output, not "Hello World".
Some types are mutable, in which case you can modify an object passed into a function. For immutable types (such as String
), you would have to build some sort of wrapper class that you can pass around instead:
class Holder<T> {
public Holder(T value) {
this.value = value;
}
public T value;
}
Then you can instead pass around the holder:
public static void main(String[] args) {
String x = "foo";
Holder<String> h = new Holder(x);
getString(h);
System.out.println(h.value);
}
public static void getString(Holder<String> output){
output.value = "Hello World"
}