String类型可以和8中基本数据类型做运算(byte/short/char/int/long/float/double/boolean),且只能是连接运算
char c = ‘a‘; int num = 10; String str = "hello"; System.out.println(c + str + num); //ahello10 System.out.println(str + (c + num));//hello107 System.out.println(c + num + str);//107hello
2.输出 “* *”这样的一个字符串，其中字符串中间的空白是制表符
System.out.println("* *");//成功
System.out.println(‘*‘ + ‘\t‘ + ‘*‘);//93
System.out.println(‘*‘ + ‘\t‘ + "*");//51*,右上一行和本行，可得到*的ascii码值为42
System.out.println(‘*‘ + "\t" + ‘*‘);//成功
System.out.println("*" + ‘\t‘ + ‘*‘);//成功
System.out.println(‘*‘ + (‘\t‘ + "*"));//成功
原文：https://www.cnblogs.com/Sinkinghost/p/10987607.html