public class HelloWorld {
public static void main(String[] args) {
System.out.println("打印直角三角形");
for(int a=1;a<=3;a++){
for(int b=1;b<=a;b++){
System.out.println("*");
}
System.out.println();
println要改为print
懂了懂了,print才是输出,println是输出并换行