写出do-while语句的句法结构，写一个关于do-while的练习

public class E_18_dowhile {
	public static void main(String[] args) {
		int i = 1;
		//i<=4则输出
		do {
			System.out.println("第 " + (i++) + "次循环");
		}while(i <= 4);
		System.out.println("======分割线======");
		i = 1;//还原初始值
		do {
			System.out.println("会被输出吗？");
		} while (i < 0);
	}
}