The code ArrayList [ ] a = new ArrayList[100]; A) will not compile B) compiles correctly,but causes a runtime exception when the program is executed C) compiles and runs correctly,but is inefficient D) compiles and runs correctly and efficiently

Question

The code ArrayList< String > [ ] a = new ArrayList< String >[100]; A) will not compile B) compiles correctly,but causes a runtime exception when the program is executed C) compiles and runs correctly,but is inefficient D) compiles and runs correctly and efficiently

Quizplus · Accepted Answer

The statement declares an array of 100 ArrayLists of Strings. The declaration is correct syntactically, but it is not a good practice to create an array of generic collections such as ArrayList. It is better to create an array of interfaces or abstract classes and then use the implementation class to create the objects. Also, the array is never initialized, and thus will produce a NullPointerException at the time of accessing any element of the array.

The Code ArrayList< String > [ ] a = New ArrayList< String