diff --git a/java-strings/src/main/java/com/baeldung/string/removeleadingtrailingchar/RemoveLeadingAndTrailingZeroes.java b/java-strings/src/main/java/com/baeldung/string/removeleadingtrailingchar/RemoveLeadingAndTrailingZeroes.java new file mode 100644 index 0000000000..c9d748e897 --- /dev/null +++ b/java-strings/src/main/java/com/baeldung/string/removeleadingtrailingchar/RemoveLeadingAndTrailingZeroes.java @@ -0,0 +1,103 @@ +package com.baeldung.string.removeleadingtrailingchar; + + +import org.apache.commons.lang3.StringUtils; + +import com.google.common.base.CharMatcher; + +public class RemoveLeadingAndTrailingZeroes { + + public static String removeLeadingZeroesWithStringBuilder(String s) { + StringBuilder sb = new StringBuilder(s); + + while (sb.length() > 1 && sb.charAt(0) == '0') { + sb.deleteCharAt(0); + } + + return sb.toString(); + } + + public static String removeTrailingZeroesWithStringBuilder(String s) { + StringBuilder sb = new StringBuilder(s); + + while (sb.length() > 1 && sb.charAt(sb.length() - 1) == '0') { + sb.setLength(sb.length() - 1); + } + + return sb.toString(); + } + + public static String removeLeadingZeroesWithSubstring(String s) { + int index = 0; + + for (; index < s.length() - 1; index++) { + if (s.charAt(index) != '0') { + break; + } + } + + return s.substring(index); + } + + public static String removeTrailingZeroesWithSubstring(String s) { + int index = s.length() - 1; + + for (; index > 0; index--) { + if (s.charAt(index) != '0') { + break; + } + } + + return s.substring(0, index + 1); + } + + public static String removeLeadingZeroesWithApacheCommonsStripStart(String s) { + String stripped = StringUtils.stripStart(s, "0"); + + if (stripped.isEmpty() && !s.isEmpty()) { + return "0"; + } + + return stripped; + } + + public static String removeTrailingZeroesWithApacheCommonsStripEnd(String s) { + String stripped = StringUtils.stripEnd(s, "0"); + + if (stripped.isEmpty() && !s.isEmpty()) { + return "0"; + } + + return stripped; + } + + public static String removeLeadingZeroesWithGuavaTrimLeadingFrom(String s) { + String stripped = CharMatcher.is('0') + .trimLeadingFrom(s); + + if (stripped.isEmpty() && !s.isEmpty()) { + return "0"; + } + + return stripped; + } + + public static String removeTrailingZeroesWithGuavaTrimTrailingFrom(String s) { + String stripped = CharMatcher.is('0') + .trimTrailingFrom(s); + + if (stripped.isEmpty() && !s.isEmpty()) { + return "0"; + } + + return stripped; + } + + public static String removeLeadingZeroesWithRegex(String s) { + return s.replaceAll("^0+(?!$)", ""); + } + + public static String removeTrailingZeroesWithRegex(String s) { + return s.replaceAll("(?!^)0+$", ""); + } +} diff --git a/java-strings/src/test/java/com/baeldung/string/removeleadingtrailingchar/RemoveLeadingAndTrailingZeroesUnitTest.java b/java-strings/src/test/java/com/baeldung/string/removeleadingtrailingchar/RemoveLeadingAndTrailingZeroesUnitTest.java new file mode 100644 index 0000000000..55f932fea1 --- /dev/null +++ b/java-strings/src/test/java/com/baeldung/string/removeleadingtrailingchar/RemoveLeadingAndTrailingZeroesUnitTest.java @@ -0,0 +1,143 @@ +package com.baeldung.string.removeleadingtrailingchar; + +import static org.assertj.core.api.Assertions.assertThat; + +import java.util.stream.Stream; + +import org.junit.jupiter.params.ParameterizedTest; +import org.junit.jupiter.params.provider.Arguments; +import org.junit.jupiter.params.provider.MethodSource; + +public class RemoveLeadingAndTrailingZeroesUnitTest { + + public static Stream leadingZeroTestProvider() { + return Stream.of(Arguments.of("", ""), Arguments.of("abc", "abc"), Arguments.of("123", "123"), Arguments.of("0abc", "abc"), Arguments.of("0123", "123"), Arguments.of("0000123", "123"), Arguments.of("1230", "1230"), Arguments.of("01230", "1230"), Arguments.of("01", "1"), + Arguments.of("0001", "1"), Arguments.of("0", "0"), Arguments.of("00", "0"), Arguments.of("0000", "0"), Arguments.of("12034", "12034"), Arguments.of("1200034", "1200034"), Arguments.of("0012034", "12034"), Arguments.of("1203400", "1203400")); + } + + public static Stream trailingZeroTestProvider() { + return Stream.of(Arguments.of("", ""), Arguments.of("abc", "abc"), Arguments.of("123", "123"), Arguments.of("abc0", "abc"), Arguments.of("1230", "123"), Arguments.of("1230000", "123"), Arguments.of("0123", "0123"), Arguments.of("01230", "0123"), Arguments.of("10", "1"), + Arguments.of("1000", "1"), Arguments.of("0", "0"), Arguments.of("00", "0"), Arguments.of("0000", "0"), Arguments.of("12034", "12034"), Arguments.of("1200034", "1200034"), Arguments.of("0012034", "0012034"), Arguments.of("1203400", "12034")); + } + + @ParameterizedTest + @MethodSource("leadingZeroTestProvider") + public void givenTestStrings_whenRemoveLeadingZeroesWithStringBuilder_thenReturnWithoutLeadingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeLeadingZeroesWithStringBuilder(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("trailingZeroTestProvider") + public void givenTestStrings_whenRemoveTrailingZeroesWithStringBuilder_thenReturnWithoutTrailingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeTrailingZeroesWithStringBuilder(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("leadingZeroTestProvider") + public void givenTestStrings_whenRemoveLeadingZeroesWithSubstring_thenReturnWithoutLeadingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeLeadingZeroesWithSubstring(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("trailingZeroTestProvider") + public void givenTestStrings_whenRemoveTrailingZeroesWithSubstring_thenReturnWithoutTrailingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeTrailingZeroesWithSubstring(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("leadingZeroTestProvider") + public void givenTestStrings_whenRemoveLeadingZeroesWithApacheCommonsStripStart_thenReturnWithoutLeadingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeLeadingZeroesWithApacheCommonsStripStart(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("trailingZeroTestProvider") + public void givenTestStrings_whenRemoveTrailingZeroesWithApacheCommonsStripEnd_thenReturnWithoutTrailingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeTrailingZeroesWithApacheCommonsStripEnd(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("leadingZeroTestProvider") + public void givenTestStrings_whenRemoveLeadingZeroesWithGuavaTrimLeadingFrom_thenReturnWithoutLeadingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeLeadingZeroesWithGuavaTrimLeadingFrom(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("trailingZeroTestProvider") + public void givenTestStrings_whenRemoveTrailingZeroesWithGuavaTrimTrailingFrom_thenReturnWithoutTrailingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeTrailingZeroesWithGuavaTrimTrailingFrom(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("leadingZeroTestProvider") + public void givenTestStrings_whenRemoveLeadingZeroesWithRegex_thenReturnWithoutLeadingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeLeadingZeroesWithRegex(input); + + // then + assertThat(result).isEqualTo(expected); + } + + @ParameterizedTest + @MethodSource("trailingZeroTestProvider") + public void givenTestStrings_whenRemoveTrailingZeroesWithRegex_thenReturnWithoutTrailingZeroes(String input, String expected) { + // given + + // when + String result = RemoveLeadingAndTrailingZeroes.removeTrailingZeroesWithRegex(input); + + // then + assertThat(result).isEqualTo(expected); + } + +}