删除Java中的前导零
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Remove leading zero in Java
提问by DataJ
public static String removeLeadingZeroes(String value):
Given a valid, non-empty input, the method should return the input with all leading zeroes removed. Thus, if the input is “0003605”, the method should return “3605”. As a special case, when the input contains only zeroes (such as “000” or “0000000”), the method should return “0”
给定一个有效的非空输入，该方法应返回删除所有前导零的输入。因此，如果输入为“0003605”，则该方法应返回“3605”。作为一种特殊情况，当输入仅包含零（例如“000”或“0000000”）时，该方法应返回“0”
public class NumberSystemService {
/**
*
* Precondition: value is purely numeric
* @param value
* @return the value with leading zeroes removed.
* Should return "0" for input being "" or containing all zeroes
*/
public static String removeLeadingZeroes(String value) {
while (value.indexOf("0")==0)
value = value.substring(1);
return value;
}
I don't know how to write codes for a string "0000".
我不知道如何为字符串“0000”编写代码。
采纳答案by John C
I would consider checking for that case first. Loop through the string character by character checking for a non "0" character. If you see a non "0" character use the process you have. If you don't, return "0". Here's how I would do it (untested, but close)
我会考虑先检查这种情况。逐字符循环遍历字符串，检查非“0”字符。如果您看到非“0”字符，请使用您拥有的过程。如果不这样做，则返回“0”。这是我的方法（未经测试，但已关闭）
boolean allZero = true;
for (int i=0;i<value.length() && allZero;i++)
{
if (value.charAt(i)!='0')
allZero = false;
}
if (allZero)
return "0"
...The code you already have
回答by Mureinik
You could add a check on the string's length:
您可以添加对字符串长度的检查：
public static String removeLeadingZeroes(String value) {
while (value.length() > 1 && value.indexOf("0")==0)
value = value.substring(1);
return value;
}
回答by Syam S
If the string always contains a valid integer the return new Integer(value).toString();is the easiest.
如果字符串始终包含有效整数，return new Integer(value).toString();则这是最简单的。
public static String removeLeadingZeroes(String value) {
return new Integer(value).toString();
}
回答by Anand Kulkarni
You can use pattern matcher to check for strings with only zeros.
您可以使用模式匹配器来检查只有零的字符串。
public static String removeLeadingZeroes(String value) {
if (Pattern.matches("[0]+", value)) {
return "0";
} else {
while (value.indexOf("0") == 0) {
value = value.substring(1);
}
return value;
}
}
回答by anirban.at.web
You can try this:
1. If the numeric value of the string is 0 then return new String("0").
2. Else remove the zeros from the string and return the substring.
您可以尝试这样做：
1. 如果字符串的数值为 0，则返回 new String("0")。
2. 否则从字符串中删除零并返回子字符串。
public static String removeLeadingZeroes(String str)
{
if(Double.parseDouble(str)==0)
return new String("0");
else
{
int i=0;
for(i=0; i<str.length(); i++)
{
if(str.charAt(i)!='0')
break;
}
return str.substring(i, str.length());
}
}
回答by Samarth Urs
private String trimLeadingZeroes(inputStringWithZeroes){
final Integer trimZeroes = Integer.parseInt(inputStringWithZeroes);
return trimZeroes.toString();
}
回答by tfarooqi
Use String.replaceAll(), like this:
使用 String.replaceAll()，像这样：
public String replaceLeadingZeros(String s) {
s = s.replaceAll("^[0]+", "");
if (s.equals("")) {
return "0";
}
return s;
}
This will match all leading zeros (using regex ^[0]+) and replace them all with blanks. In the end if you're only left with a blank string, return "0" instead.
这将匹配所有前导零（使用正则表达式 ^[0]+）并将它们全部替换为空格。最后，如果您只剩下一个空白字符串，请改为返回“0”。
回答by Aman Systematix
You can use below replace function it will work on a string having both alphanumeric or numeric
您可以使用下面的替换函数，它可以处理具有字母数字或数字的字符串
s.replaceFirst("^0+(?!$)", "")
回答by DwB
- Stop reinventing the wheel. Almost no software development problem you ever encounter will be the first time it has been encountered; instead, it will only be the first time you encounter it.
- Almost everything utility method you ever need has already been written by the Apache project and/or the guava project.
- Read the Apache StringUtils JavaDoc page. This utility is likely to already provide every string manipulation functionality you will ever need
- 停止重新发明轮子。您遇到的几乎所有软件开发问题都不会是第一次遇到；相反，它只会是您第一次遇到它。
- Apache 项目和/或 guava 项目几乎已经编写了您需要的几乎所有实用程序方法。
- 阅读Apache StringUtils JavaDoc 页面。此实用程序可能已经提供了您将需要的所有字符串操作功能
Some example code to solve your problem:
一些示例代码来解决您的问题：
public String stripLeadingZeros(final String data)
{
final String strippedData;
strippedData = StringUtils.stripStart(data, "0");
return StringUtils.defaultString(strippedData, "0");
}
回答by Ketan Ramani
public String removeLeadingZeros(String digits) {
//String.format("%.0f", Double.parseDouble(digits)) //Alternate Solution
String regex = "^0+";
return digits.replaceAll(regex, "");
}
removeLeadingZeros("0123"); //Result -> 123
removeLeadingZeros("00000456"); //Result -> 456
removeLeadingZeros("000102030"); //Result -> 102030
