Check for All Uppercase/Lowercase in Java

Using Standard JDK

public static boolean isUpperCase(String s) {
    for (int i = 0; i < s.length(); i++) {
        if (Character.isLowerCase(s.charAt(i)))
            return false;
    }

    return true;
}

NOTE: There are also alternatives using Apache Commons or Guava libraries, but they may run into issues when the string contains punctuations/other symbols.

Reference

• Is there an existing library method that checks if a String is all upper case or lower case in Java? - Stack Overflow

Published

Tags

• java 9

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