删除java代码中的前导零
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Removing leading zero in java code
提问by user3835327
May I know how can I remove the leading zero in JAVA code? I tried several methods like regex tools
我可以知道如何删除 JAVA 代码中的前导零吗？我尝试了几种方法，例如正则表达式工具
"s.replaceFirst("^0+(?!$)", "") / replaceAll("^0*", "");`
but it's seem like not support with my current compiler compliance level (1.3), will have a red line stated the method replaceFirst(String,String)is undefined for the type String.
但似乎不支持我当前的编译器合规性级别 (1.3)，会有一条红线表明方法 replaceFirst(String,String) 未定义为 String 类型。
Part of My Java code
我的 Java 代码的一部分
public String proc_MODEL(Element recElement)
{
String SEAT = "";
try
{
SEAT = setNullToString(recElement.getChildText("SEAT")); // xml value =0000500
if (SEAT.length()>0)
{
SEAT = SEAT.replaceFirst("^0*", ""); //I need to remove leading zero to only 500
}
catch (Exception e)
{
e.printStackTrace();
return "501 Exception in proc_MODEL";
}
}
}
Appreciate for help.
感谢帮助。
采纳答案by Elliott Frisch
If you want remove leading zeros, you could parse to an Integerand convert back to a Stringwith one line like
如果你想删除前导零，你可以解析为一个Integer并转换回String一个像
String seat = "001";// setNullToString(recElement.getChildText("SEAT"));
seat = Integer.valueOf(seat).toString();
System.out.println(seat);
Output is
输出是
1
Of course if you intend to use the value it's probably better to keep the int
当然，如果您打算使用该值，最好保留 int
int s = Integer.parseInt(seat);
System.out.println(s);
回答by paxdiablo
replaceFirst()was introduced in 1.4 and your compiler pre-dates that.
replaceFirst()是在 1.4 中引入的，而您的编译器早于它。
One possibility is to use something like:
一种可能性是使用类似的东西：
public class testprog {
public static void main(String[] args) {
String s = "0001000";
while ((s.length() > 1) && (s.charAt(0) == '0'))
s = s.substring(1);
System.out.println(s);
}
}
It's not the most efficient code in the world but it'll get the job done.
它不是世界上最高效的代码，但它可以完成工作。
A more efficient segment without unnecessary string creation could be:
没有不必要的字符串创建的更有效的段可能是：
public class testprog {
public static void main(String[] args) {
String s = "0001000";
int pos = 0;
int len = s.length();
while ((pos < len-1) && (s.charAt(pos) == '0'))
pos++;
s = s.substring(pos);
System.out.println(s);
}
}
Both of those also handle the degenerate cases of an empty string and a string containing only0characters.
两者都处理空字符串和仅包含0字符的字符串的退化情况。
回答by jondinham
As stated in Java documentation, 'replaceFirst' only started existing since Java 1.4 http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#replaceFirst(java.lang.String,%20java.lang.String)
如 Java 文档中所述，“replaceFirst”仅从 Java 1.4 http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#replaceFirst(java.lang.String,% 20java.lang.String)
Use this function instead:
改用这个函数：
String removeLeadingZeros(String str) {
while (str.indexOf("0")==0)
str = str.substring(1);
return str;
}
回答by ps2090
Using a java method str.replaceAll("^0+(?!$)", "")would be simple;
使用 java 方法str.replaceAll("^0+(?!$)", "")会很简单；
First parameter:regex -- the regular expression to which this string is to be matched.
First parameter:regex -- 与此字符串匹配的正则表达式。
Second parameter: replacement -- the string which would replace matched expression.
Second parameter:replacement -- 将替换匹配表达式的字符串。
