Android: How to set a default value for an argument variable

Question

Android function

PHP example:

function HaHa($a = "Test")
{
    print $a; 
}

The question is how to do it in android...

public void someFunction(int ttt = 5)
{
   // something
}

The solution above doesn't work, how can I do it?

Thanks!

Solution 1

No, Java does not support default values for function parameteres. There's an interesting post about borrowing language features here: http://java.dzone.com/news/default-argument-values-java

Solution 2

No need to overload anything, just write:

public int getScore(int score, Integer... bonus)
{
    if(bonus.length > 0)
    {
        return score + bonus[0];
    }
    else
    {
        return score;
    }
}

Solution 3

You can abuse overloading like this:

int someMethod() { return someMethod(42); }
int someMethod(int arg) { .... }

Solution 4

you can use 3 dots syntax:

public void doSomething(boolean... arg1) {
    boolean MyArg1= (arg1.length >= 1) ? arg1 : false;
}

Solution 5

You can do it now in Android by using Kotlin! Kotlin supports default arguments, so you can write a function like:

fun addTheBook(title: String, author : String = "No Name"){...}

And then you can call it just like:

addTheBook("The Road Less Traveled")

View more solutions

Comments

[M.V.]

I thought so but native functions support it somehow... I can't actually remember one... Or for example JSONArray can be built from different sources: String, JSONTokener x, Collection collection or blank... I thought there could be work around

[M.V.]

Well work around for me is to put String[] inside and can add or remove arguments...

[Sithu]

I think this is better. It can be simplified such as return bonus.length > 0 ? score + bonus[0] : score;

[Mahdi-Malv]

I like your way.