CODEWITHSUNDEEP
javavariablesargumentsdefault
M.V.
M.V.

Reputation: 1672

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

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!

Upvotes: 21

Views: 49708

Answers (7)

Zibi
Zibi

Reputation: 544

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")

Upvotes: 1

T.Todua
T.Todua

Reputation: 56371

you can use 3 dots syntax:

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

Upvotes: 5

Jigar Shah
Jigar Shah

Reputation: 79

You can use overloading a function . The overloading is also okay but in case you need default values for multiple arguments you will end up creating having many methods with all possible combination of default arguments, for the example you use imagine you want to have a default value for the 3 arguments. you will end up with this

public void methodA(A arg1) {  }
public void methodA( B arg2,) {  }
public void methodA(C arg3) {  }
public void methodA(A arg1, B arg2) {  }
public void methodA(A arg1, C arg3) {  }
public void methodA( B arg2, C arg3) {  }
public void methodA(A arg1, B arg2, C arg3) {  }

So here's the hack i did for me , you can also use

public static void main(String[] args)
{
    defaultParameter();
    defaultParameter(true);
}

public static void defaultParameter(Boolean ...gender)
{
    boolean genderBoolean  = false; // It the default value you want to give
    if(gender.length == 1)
    {
        genderBoolean = gender[0];  // Overrided Value
    }
    System.out.println(genderBoolean);
}

The above code will genrate result 

false
true

I find out here the example java-default-parameter-values

Upvotes: 1

Hamzeh Soboh
Hamzeh Soboh

Reputation: 7710

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;
    }
}

Upvotes: 15

Ingo
Ingo

Reputation: 36339

You can abuse overloading like this:

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

Upvotes: 14

Thane Anthem
Thane Anthem

Reputation: 4093

Java doesn't support a syntax that will do what you want.

Perhaps at the start of someFunction(int), you could just check the incoming value, and assign a different value if you don't like what's coming in.

if (ttt == 0) ttt = 5;

Please note this question appears to have nothing to do with android, and so is improperly tagged.

Upvotes: 0

Bendihossan
Bendihossan

Reputation: 2497

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

Upvotes: 15

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