java 中 lastIndexOf(obj o) 方法的作用是什么?
**java.util.ArrayList** 类中的 **lastIndexOf(Object)** 方法返回此列表中指定元素最后出现处的索引,如果此列表不包含该元素,则返回 -1。
示例
import java.util.ArrayList; public class ArrayListDemo { public static void main(String[] args) { ArrayList<String> arrlist = new ArrayList<String>(5); arrlist.add("G"); arrlist.add("E"); arrlist.add("F"); arrlist.add("M"); arrlist.add("E"); System.out.println("Size of list: " + arrlist.size()); for (String value : arrlist) { System.out.println("Value = " + value); } int retval=arrlist.lastIndexOf("E"); System.out.println("The last occurrence of E is at index " + retval); } }
输出
Size of list: 5 Value = G Value = E Value = F Value = M Value = E The last occurrence of E is at index 4
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