java 是否可以将 0001 存储在 int 中？
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Is it possible to store 0001 in int?
提问by Gokul Nath KP
The product (25 years old product) I am working on is very large and complicated. So let me explain what I want in simple scenario:
我正在开发的产品（25 年的产品）非常庞大且复杂。所以让我在简单的场景中解释我想要什么：
I've declared an intvariable. Say, int var = 0001;
我已经声明了一个int变量。说，int var = 0001;
When we try to retrieve the value of var, we'll get 1.
当我们尝试检索 的值时var，我们会得到1。
Now, my requirement is, is it possible to return 0001, without changing the signature or return type of the method?
现在，我的要求是，是否可以在0001不更改方法的签名或返回类型的情况下返回？
回答by Maarty
if you know how much digits number have you can use
如果你知道你可以使用多少位数
String.format("%04d", number);
int will allways return 1
int 总是返回 1
回答by Boris the Spider
You cannot store 0001as an int.
您不能存储0001为int.
An intstores a number, i.e. 1. You need a format.
Anint存储一个数字，即1。你需要一个格式。
When you "retrieve" your intyou implicitly Integer.toString()it; this is the point at which you need to tell Java how to format it.
当你“检索”你的时候，int你就隐含了Integer.toString()它；这是您需要告诉 Java 如何格式化它的地方。
You haven't really given any information but I suppose you always need 4 digits, in this case the format mask 0000ought to do the trick.
您还没有真正提供任何信息，但我想您总是需要 4 位数字，在这种情况下，格式掩码0000应该可以解决问题。
public static void main(String[] args) throws Exception {
final int i = 1;
final DecimalFormat decimalFormat = new DecimalFormat("0000");
System.out.println(decimalFormat.format(i));
}
Output:
输出：
0001
回答by Dmitry Bychenko
Do not start numbers from 0 - in Java they considered to be octal (base 8)- unless you have strange outcomes, e.g.:
不要从 0 开始数字 - 在 Java 中他们认为是八进制（以 8为底）- 除非你有奇怪的结果，例如：
001 == 1
010 == 8 // Octal 10 == Decimal 8
0123 == 83 // Octal 123 is Decimal 83
08 - error! This's not an octal value
001 == 1
010 == 8 // 八进制 10 == 十进制 8
0123 == 83 // 八进制 123 是十进制 83
08 - error! This's not an octal value
etc.
等等。
Instead use formattingwhenever you want to print out your number
每当您想打印您的号码时，请改用格式
int number = 1; // <- Just a decimal integer
String result = String.form("My number is %04d in dddd format", number);
回答by Esko
Two possibilities:
两种可能：
- The value is actually octal and you need to take care of conversions etc. or
- This is just a data presentation problem and you need to transform it into a string with required left padding before interacting with the system that's almost as old as I am.
- 该值实际上是八进制，您需要处理转换等或
- 这只是一个数据呈现问题，在与几乎和我一样古老的系统进行交互之前，您需要将其转换为具有所需左填充的字符串。
回答by Masudul
Before zero of an int treat as Octal in Java. So, You cannot store 0001 as an int.
在 Java 中 int 的零之前视为八进制。因此，您不能将 0001 存储为 int。
回答by Berk Aydin
If you know the exact length of the number. For example 6.
如果您知道数字的确切长度。例如 6。
int x = 5
String s = "";
s = ""+x;
while(s.length() < 6){
s = "0"+s;
}
This will print 000005.
这将打印 000005。
回答by ALLU AJAY KUMAR
After some lookout i found an working answer.
经过一番观察，我找到了一个有效的答案。
DecimalFormat df=new DecimalFormat("0000");
int i=1;
i=df.format(i);
this worked for me.
这对我有用。
