java - 有没有一种方法可以格式化您的输出，使其更加统一？

Question

我有一个很长的字符串，一切正常，但我无法获得与教授相同的输出。他的输出更均匀。所以首先我尝试做一个 system.out.println()，但是没有用。

这是我的代码:

System.out.println("Password = " + password + "\t\t" + "Newline = " + ctnline + "\t" + "Single = " + ctlength + "\t" + "Equal = " + ctequal + "\t" + "Lenght = " + ctlength2 + "\t" + "Upper = " + ctupper + "\t" + "Lower = " + ctlower + "\t" + "Special = " + (ctspec2));

这是输出:

Password = bank,Rabbither               Newline = 0     Single = 2      Equal = 0       Lenght = 1      Upper = 2       Lower = 0       Special = 1
Password = acrossShemoment,             Newline = 0     Single = 3      Equal = 0       Lenght = 2      Upper = 9       Lower = 0       Special = 0
Password = her.theyOWN          Newline = 0     Single = 6      Equal = 0       Lenght = 3      Upper = 9       Lower = 0       Special = 1
Password = ALICEeyes.said               Newline = 0     Single = 0      Equal = 0       Lenght = 0      Upper = 0       Lower = 0       Special = 0
Password = thepackKing.         Newline = 0     Single = 1      Equal = 0       Lenght = 3      Upper = 4       Lower = 0       Special = 1
Password = thethatKing.         Newline = 0     Single = 1      Equal = 0       Lenght = 0      Upper = 2       Lower = 0       Special = 0
Password = AfterWhichdear!              Newline = 0     Single = 1      Equal = 0       Lenght = 1      Upper = 3       Lower = 0       Special = 0
Password = "Silencethecrown             Newline = 0     Single = 1      Equal = 1       Lenght = 6      Upper = 8       Lower = 0       Special = 0
Password = "Silencemuchme               Newline = 0     Single = 6      Equal = 0       Lenght = 1      Upper = 6       Lower = 0       Special = 2
Password = King.nopeeped                Newline = 0     Single = 5      Equal = 0       Lenght = 2      Upper = 9       Lower = 0       Special = 2
Password = eitherKing.Soon              Newline = 0     Single = 0      Equal = 0       Lenght = 0      Upper = 0       Lower = 0       Special = 0 

那没有用，老师有一个输出，其中“换行符”对齐在一起。

我需要的输出是这样的(老师怎么写的):

Password = bank,Rabbither       Newline = 0     Single = 2      Equal = 0       Lenght = 1      Upper = 2       Lower = 0       Special = 1
Password = acrossShemoment,     Newline = 0     Single = 3      Equal = 0       Lenght = 2      Upper = 9       Lower = 0       Special = 0
Password = her.theyOWN          Newline = 0     Single = 6      Equal = 0       Lenght = 3      Upper = 9       Lower = 0       Special = 1
Password = ALICEeyes.said       Newline = 0     Single = 0      Equal = 0       Lenght = 0      Upper = 0       Lower = 0       Special = 0
Password = thepackKing.         Newline = 0     Single = 1      Equal = 0       Lenght = 3      Upper = 4       Lower = 0       Special = 1
Password = thethatKing.         Newline = 0     Single = 1      Equal = 0       Lenght = 0      Upper = 2       Lower = 0       Special = 0
Password = AfterWhichdear!      Newline = 0     Single = 1      Equal = 0       Lenght = 1      Upper = 3       Lower = 0       Special = 0
Password = "Silencethecrown     Newline = 0     Single = 1      Equal = 1       Lenght = 6      Upper = 8       Lower = 0       Special = 0
Password = "Silencemuchme       Newline = 0     Single = 6      Equal = 0       Lenght = 1      Upper = 6       Lower = 0       Special = 2
Password = King.nopeeped        Newline = 0     Single = 5      Equal = 0       Lenght = 2      Upper = 9       Lower = 0       Special = 2
Password = eitherKing.Soon      Newline = 0     Single = 0      Equal = 0       Lenght = 0      Upper = 0       Lower = 0       Special = 0 

我从来没有学过如何使用 printf，当我查找解决方案时，他们就是这样在网上展示它的。有没有其他方法可以在打印时正确格式化。我不确定我们是否可以使用 printf，因为老师从未教过它。

编辑:我可以使用 String.format() 方法。

Answer 1

您可以使用 System.out.printf()。它使用与 String.format() 相同的代码。

System.out.printf("Password = %20s Newline = %2d Single = %d Equal = %d Lenght = %d Upper = %d Lower = %d Special = %d\n",
    password, ctnline, ctlength, ctequal, ctlength2, ctupper, ctlower, ctspec2);

格式字符串采用您喜欢的任何文本加上以 %s 开头的代码。您最常使用的两个是 %s——一个字符串——和 %d——一个十进制数。您可以在 google 上搜索 printf 格式字符串以进行更长时间的讨论。 %f 不太常见，但仍然很重要。我将在下面讨论。

%s 或 %d 可以采用可选长度。您会看到我做了 %20s——这意味着空格填充到 20 个字符，即使传入的字符串为空。你可以用数字做同样的事情。如果您不指定长度，它将根据需要使用多少。如果您指定的不够多，它将运行很长时间。

您可以用零填充数字，例如 %03d。例如，这会给你 004 而不是 4。

您可以使用 - 操作左对齐和右对齐。 %-20s，例如。

此时，我会进行实验。

对于 float (1.5)，您执行 %f。

System.out.printf("%3.1f\n", 1.5);

在这个例子中，3是整个宽度，1是小数点后的位数。所以 %1​​0.2f 会给你 10 个字符宽和小数点后 2 点。