丝滑去除字符串前后为0的算法

项目中随时会用到，作为笔记留存。

去掉字符串前面为0

1、substring方法

public class RemoveLeadingZeros {public static void main(String[] args) {String input = "000abc000";String result = removeLeadingZeros(input);System.out.println("源string: " + input);System.out.println("新string: " + result);}/*** 去除字符串前面的全零* @param input 输入字符串* @return 处理后的字符串*/public static String removeLeadingZeros(String input) {if (input == null || input.isEmpty()) {return "";}StringBuilder sb = new StringBuilder(input);int start = 0;// 找到第一个非零字符的开始位置while (start < sb.length() && sb.charAt(start) == '0') {start++;}// 返回从非零字符开始的子字符串return sb.substring(start);}
}

2、使用正则表达式

public class RemoveLeadingZeros {public static void main(String[] args) {String input = "00012345";String result = input.replaceAll("0+", "");System.out.println(result); // 输出 "12345"}
}

去掉字符串前后为0

1、使用substring

public class RemoveTrailingZeros {public static void main(String[] args) {String input = "abc000";String result = removeTrailingZeros(input);System.out.println("源string: " + input);System.out.println("新string: " + result);}/*** 去除字符串末尾的全零* @param input 输入字符串* @return 处理后的字符串*/public static String removeTrailingZeros(String input) {if (input == null || input.isEmpty()) {return "";}int end = input.length() - 1;// 找到最后一个非零字符的结束位置while (end >= 0 && input.charAt(end) == '0') {end--;}// 返回从字符串开始到 end 的子字符串return end >= 0 ? input.substring(0, end + 1) : "";}
}

2、使用正则表达式

public class RemoveTrailingZerosWithRegex {public static void main(String[] args) {String input = "12345000";String result = removeTrailingZeros(input);System.out.println(result); // 输出 "12345"}public static String removeTrailingZeros(String str) {// 使用正则表达式替换末尾的零// 正则表达式 "0+$" 匹配字符串末尾的一个或多个零return str.replaceAll("0+$", "");}
}

去掉中间为0

1、使用append

public class RemoveMiddleZeros {public static String removeMiddleZeros(String input) {if (input == null || input.isEmpty()) {return input;}// 将字符串转换为字符数组char[] chars = input.toCharArray();int length = chars.length;// 找到第一个非0字符的位置int start = 0;while (start < length && chars[start] == '0') {start++;}// 找到最后一个非0字符的位置int end = length - 1;while (end >= 0 && chars[end] == '0') {end--;}// 如果整个字符串都是0，直接返回原字符串if (start > end) {return input;}// 构建新的字符串，去掉中间的0StringBuilder result = new StringBuilder();for (int i = 0; i < start; i++) {result.append(chars[i]);}for (int i = start; i <= end; i++) {if (chars[i] != '0') {result.append(chars[i]);}}for (int i = end + 1; i < length; i++) {result.append(chars[i]);}return result.toString();}public static void main(String[] args) {String input = "00012304560078000";String output = removeMiddleZeros(input);System.out.println(output);  // 输出: 00012345678000}
}

2、使用正则表达式

public class RemoveMiddleZerosWithRegex {public static String removeMiddleZeros(String input) {if (input == null || input.isEmpty()) {return input;}// 正则表达式：匹配中间的0，但不匹配开头和结尾的0String regex = "(?<=.)0+(?=.)";return input.replaceAll(regex, "");}public static void main(String[] args) {String input = "00012304560078000";String output = removeMiddleZeros(input);System.out.println(output);  // 输出: 00012345678000}
}