[OCAJP]StringBuilder2

Given:

public class Whizlabs {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder("1Z0");
        sb.concat("-808");
        System.out.println(sb);
    }
}

What is the output?

A.

B.

C. An exception will be thrown.
D. Compilation fails due to error at line 3.
E. Compilation fails due to error at line 4.

題解

StringBuilder物件並沒有「concat」方法，因此程式第4行會編譯錯誤。如果要串接字串應使用StringBuilder的「append」方法。