String array initialization as constructor paramet

问题:

This question already has answers here:

Array initialization syntax when not in a declaration (4 answers)

Closed 4 years ago.

In Java, it is completely legal to initialize a String array in the following way:

String[] s = {"FOO", "BAR"};

However, when trying to instantiate a class that takes a String array as a parameter, the following piece of code is NOT allowed:

Test t = new Test({"test"});

But this works again:

Test t = new Test(new String[] {"test"});

Can someone explain why this is?

回答1:

String[] s = {"FOO", "BAR"};  

this is allowed at declaration time only

You can't

String[] s;
s={"FOO", "BAR"};  

回答2:

Because Type[] x = { ... } is an initialization syntax for arrays. The { ... } is interpreted in a specific way only in that specific context.

回答3:

For you want a simple way to pass a String array, I suggest you use varargs

class Test {
   public Test(String...args);
}

// same as new Test(new String[] { "test", "one" })
Test t = new Test("test", "one");