字符串的 Java 输出格式
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Java output formatting for Strings
提问by Steffan Harris
I was wondering if someone can show me how to use the format method for Java Strings. For instance If I want the width of all my output to be the same
我想知道是否有人可以告诉我如何使用 Java 字符串的格式方法。例如，如果我希望所有输出的宽度相同
For instance, Suppose I always want my output to be the same
例如，假设我总是希望我的输出相同
Name = Bob
Age = 27
Occupation = Student
Status = Single
In this example, all the output are neatly formatted under each other; How would I accomplish this with the format method.
在这个例子中，所有的输出都整齐地排列在彼此之下；我将如何使用 format 方法完成此操作。
采纳答案by gnomed
EDIT: This is an extremely primitive answer but I can't delete it because it was accepted. See the answers below for a better solution though
编辑：这是一个非常原始的答案，但我无法删除它，因为它已被接受。请参阅下面的答案以获得更好的解决方案
Why not just generate a whitespace string dynamically to insert into the statement.
为什么不直接生成一个空白字符串来插入到语句中。
So if you want them all to start on the 50th character...
所以如果你想让它们都从第 50 个字符开始......
String key = "Name =";
String space = "";
for(int i; i<(50-key.length); i++)
{space = space + " ";}
String value = "Bob\n";
System.out.println(key+space+value);
Put all of that in a loop and initialize/set the "key" and "value" variables before each iteration and you're golden. I would also use the StringBuilderclass too which is more efficient.
将所有这些放在一个循环中，并在每次迭代之前初始化/设置“键”和“值”变量，你就很成功了。我也会使用StringBuilder更有效的类。
回答by I82Much
If you want a minimum of 4 characters, for instance,
例如，如果您想要至少 4 个字符，
System.out.println(String.format("%4d", 5));
// Results in " 5", minimum of 4 characters
回答by stacker
System.out.println(String.format("%-20s= %s" , "label", "content" ));
- Where %s is a placeholder for you string.
- The '-' makes the result left-justified.
- 20 is the width of the first string
- 其中 %s 是您字符串的占位符。
- '-' 使结果左对齐。
- 20 是第一个字符串的宽度
The output looks like this:
输出如下所示：
label = content
As a reference I recommend Javadoc on formatter syntax
作为参考，我推荐关于格式化程序语法的 Javadoc
回答by Peter Lawrey
To answer your updated question you can do
要回答您更新的问题，您可以这样做
String[] lines = ("Name = Bob\n" +
"Age = 27\n" +
"Occupation = Student\n" +
"Status = Single").split("\n");
for (String line : lines) {
String[] parts = line.split(" = +");
System.out.printf("%-19s %s%n", parts[0] + " =", parts[1]);
}
prints
印刷
Name = Bob
Age = 27
Occupation = Student
Status = Single
回答by Roman
For decimal values you can use DecimalFormat
对于十进制值，您可以使用 DecimalFormat
import java.text.*;
public class DecimalFormatDemo {
static public void customFormat(String pattern, double value ) {
DecimalFormat myFormatter = new DecimalFormat(pattern);
String output = myFormatter.format(value);
System.out.println(value + " " + pattern + " " + output);
}
static public void main(String[] args) {
customFormat("###,###.###", 123456.789);
customFormat("###.##", 123456.789);
customFormat("000000.000", 123.78);
customFormat("$###,###.###", 12345.67);
}
}
and output will be:
输出将是：
123456.789 ###,###.### 123,456.789
123456.789 ###.## 123456.79
123.78 000000.000 000123.780
12345.67 $###,###.### ,345.67
For more details look here:
更多详情请看这里：
http://docs.oracle.com/javase/tutorial/java/data/numberformat.html
http://docs.oracle.com/javase/tutorial/java/data/numberformat.html
回答by Amol Kakade
@Override
public String toString() {
return String.format("%15s /n %15d /n %15s /n %15s", name, age, Occupation, status);
}
