Deletes all whitespaces from a String as defined by Character.isWhitespace(char). : String vs Char Array « Data Type « Java Tutorial

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 * this work for additional information regarding copyright ownership.
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public class Main {

   * Deletes all whitespaces from a String as defined by
   * {@link Character#isWhitespace(char)}.
   * <pre>
   * StringUtils.deleteWhitespace(null)         = null
   * StringUtils.deleteWhitespace("")           = ""
   * StringUtils.deleteWhitespace("abc")        = "abc"
   * StringUtils.deleteWhitespace("   ab  c  ") = "abc"
   * </pre>
   * @param str  the String to delete whitespace from, may be null
   * @return the String without whitespaces, <code>null</code> if null String input
  public static String deleteWhitespace(String str) {
      if (isEmpty(str)) {
          return str;
      int sz = str.length();
      char[] chs = new char[sz];
      int count = 0;
      for (int i = 0; i < sz; i++) {
          if (!Character.isWhitespace(str.charAt(i))) {
              chs[count++] = str.charAt(i);
      if (count == sz) {
          return str;
      return new String(chs, 0, count);
  // Empty checks
   * Checks if a String is empty ("") or null.
   * <pre>
   * StringUtils.isEmpty(null)      = true
   * StringUtils.isEmpty("")        = true
   * StringUtils.isEmpty(" ")       = false
   * StringUtils.isEmpty("bob")     = false
   * StringUtils.isEmpty("  bob  ") = false
   * </pre>
   * NOTE: This method changed in Lang version 2.0.
   * It no longer trims the String.
   * That functionality is available in isBlank().
   * @param str  the String to check, may be null
   * @return <code>true</code> if the String is empty or null
  public static boolean isEmpty(String str) {
      return str == null || str.length() == 0;


2.28.String vs Char Array
2.28.1.Demonstrates the charAt and getChars
2.28.2.Converting Char array to String
2.28.3.Creating Character Arrays From String Objects
2.28.4.Copy characters from string into char Array
2.28.5.Creating String Objects From Character Arrays String(textArray, 9, 3): Creating String Objects From certain part of a character Array
2.28.7.Creating String Objects From Character Arrays using String.copyValueOf()
2.28.8.Creating a string from a subset of the array elements
2.28.9.Extracting a substring as an array of characters using the method getChars()
2.28.10.Using the Collection-Based for Loop with a String: Counting all vowels in a string
2.28.11.Construct one String from another.
2.28.12.demonstrates getChars( ):
2.28.13.implements CharSequence
2.28.14.Removes spaces (char <= 32) from end of this String with escape, handling null by returning null
2.28.15.Removes spaces (char <= 32) from end of this String, handling null by returning null
2.28.16.Swaps the case of a String changing upper and title case to lower case, and lower case to upper case.
2.28.17.Deletes all whitespaces from a String as defined by Character.isWhitespace(char).
2.28.18.Checks whether the String contains only digit characters.
2.28.19.Checks that the String does not contain certain characters.