Check if a given string is Pangram in Java

Last Updated : 16 Jan, 2026

A pangram is a string that contains every letter of the English alphabet at least once. For example, "The quick brown fox jumps over the lazy dog" is a pangram because it contains all 26 letters from a to z.

How to Check a Pangram in Java

To determine if a string is a pangram:

  1. Convert the string to lowercase (to handle case insensitivity).
  2. Check if all letters from a to z are present in the string.

Examples:

Input: str = "Abcdefghijklmnopqrstuvwxyz"
Output: Yes
Explanation: The given string contains all the letters from a to z (ignoring case).

Input: str = "GeeksForGeeks"
Output: No
Explanation: The given string does not contain all the letters from a to z (ignoring case).

Methods to check Pangram String

Method 1: Using Frequency Array

  • Convert the string to lowercase.
  • Create a boolean array of size 26 to track letters a to z.
  • Traverse the string and mark letters as present.
  • Check if all letters are marked.

Example:

Java 
class GFG {
    static int size = 26;
    static boolean isLetter(char ch) {
        return Character.isLetter(ch);
    }
    static boolean allLetter(String str, int len) {
        str = str.toLowerCase();
        boolean[] present = new boolean[size];

        for (int i = 0; i < len; i++) {
            if (isLetter(str.charAt(i))) {
                int index = str.charAt(i) - 'a';
                present[index] = true;
            }
        }

        for (int i = 0; i < size; i++) {
            if (!present[i])
                return false;
        }
        return true;
    }

    public static void main(String[] args) {
        String str = "Abcdefghijklmnopqrstuvwxyz";
        if (allLetter(str, str.length()))
            System.out.println("Yes");
        else
            System.out.println("No");
    }
}

Output
Yes

Explanation:

  • isLetter() checks whether the current character is an alphabet.
  • allLetter() converts the string to lowercase for case-insensitive checking.
  • A boolean[] present array stores whether each letter from a to z appears in the string.
  • Each character is mapped to an index using ch - 'a' and marked as true.
  • The array is checked to ensure no letter is missing.

Method 2: Using Character Traversal

  • Convert the string to lowercase.
  • Loop from 'a' to 'z'.
  • Check if each letter exists in the string using contains().
  • If any letter is missing, print No.

Example:

Java 
class GFG {
    static void allLetter(String str) {
        str = str.toLowerCase();
        boolean allPresent = true;

        for (char ch = 'a'; ch <= 'z'; ch++) {
            if (!str.contains(String.valueOf(ch))) {
                allPresent = false;
                break;
            }
        }
        if (allPresent)
            System.out.println("Yes");
        else
            System.out.println("No");
    }

    public static void main(String[] args) {
        String str = "Abcdefghijklmnopqrstuvwxyz12";
        allLetter(str);
    }
}

Output
Yes

Explanation:

  • The string is converted to lowercase to ignore case differences.
  • A boolean variable allPresent assumes all letters are present initially.
  • A loop runs from 'a' to 'z' to check every alphabet letter.
  • str.contains() checks whether each letter exists in the string.
  • If any letter is missing, allPresent is set to false and the loop stops.
  • Time Complexity: O(26*N) 
  • Auxiliary Space: O(1)
     
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