println("test")相当于print("test\n")就是一般的输出字符串 

double temp = 21.63;
            
System.out.println("Hello World");
System.out.println("temp == " + temp);
System.out.printf("1111 temp == %.1f" , temp);
System.out.print("22222 ==== " + temp);
//System.out.print("====>>>\n");

double temp = 21.63;

System.out.println("Hello World");
System.out.println("temp == " + temp);
System.out.printf("1111 temp == %.1f\n" , temp);
System.out.print("22222 ==== " + temp);
System.out.print("====>>>\n");
Log.d("111111","22222");

提示一下：我这边用的新版Android studio（2024.1.2）编译实现的