代码: List a = new ArrayList(); System.out.println("a.size()="+a.size()); System.out.println("a.get(0)="+a.get(0));
控制台结果: a.size()=0 Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 at java.util.ArrayList.RangeCheck(ArrayList.java:547) at java.util.ArrayList.get(ArrayList.java:322) at demo.test2.main(test2.java:23)