a = 12
b = 34
c = 56
System.out.println("h1 = " + a + b + c);
System.out.println("h2 = " + (a + b) + c);
System.out.println("h3 = " + ((a + b) + c));
h1 = 123456
h2 = 4656
h3 = 102
""后面记得也要加“+”！！！！！！
额。。。看的时候自动忽视“哈哈哈哈哈哈”，不再换截图了
