Pangram Program in Java

A string is known as pangram if it has all the alphabets from a to z at least once. A popular example of pangram sentence is “The quick brown fox jumps over the lazy dog”.

Here are some other examples of pangram sentences.

• “How vexingly quick daft zebras jump”
• “Bright vixens jump; dozy fowl quack”
• “Quick zephyrs blow, vexing daft Jim”
• “Sphinx of black quartz, judge my vow”
• “Five quacking zephyrs jolt my wax bed”

Now let’s have a look at how to check if a string is pangram in java.

public class Pangram {
    public static boolean isPangram(String sentence) {
        // array to store the occurrence of each letter
        boolean[] marked = new boolean[26];

        // Convert to lower case for uniformity
        String lowerCaseSentence = sentence.toLowerCase();

        // iterate over every character in the string
        for (int i = 0; i < lowerCaseSentence.length(); i++) {
            char ch = lowerCaseSentence.charAt(i);
            if ('a' <= ch && ch <= 'z') {
                marked[ch - 'a'] = true;
            }
        }

        // Check if every letter occurred at least once
        for (boolean m : marked) {
            if (!m) {
                return false;
            }
        }

        return true;
    }

    public static void main(String[] args) {
        String sentence = "The quick brown fox jumps over the lazy dog";
        if (isPangram(sentence)) {
            System.out.println("This is a pangram");
        } else {
            System.out.println("This is not a pangram");
        }
    }
}

Output:

This is a pangram

Explanation:

• First, we created a boolean array to store the occurrence of each letter. Initially, its value is false.
• We converted the string to lowercase for uniformity.
• Now we iterate through each character of the string and if it’s between a to z then we mark the corresponding index of the boolean array as true.
• After that we check each element of the boolean array, if all the elements are true then the string is pangram otherwise not.