Given a string, the task is to check whether a string contains only alphabets or not using ASCII values in JAVA.
Examples:
Input : GeeksforGeeks Output : True Input : Geeks4Geeks Output : False Input : null Output : False
In this article, the characters of the string are checked one by one using their ASCII values.
Algorithm:
- Get the string
- Match the string:
- Check if the string is empty or not. If empty, return false
- Check if the string is null or not. If null, return false.
- If the string is neither empty nor null, then check the string characters one by one for alphabet using ASCII values.
- Return true if matched
Pseudocode:
public static boolean isStringOnlyAlphabet(String str){ if (str == null || str.equals("")) { return false; } for (int i = 0; i < str.length(); i++) { char ch = str.charAt(i); if ((!(ch >= 'A' && ch <= 'Z')) && (!(ch >= 'a' && ch <= 'z'))) { return false; } } return true;} |
Program: Checking for String containing only Alphabets
// Java program to check if String contains only Alphabets// using ASCII values class GFG { // Function to check String for only Alphabets public static boolean isStringOnlyAlphabet(String str) { if (str == null || str.equals("")) { return false; } for (int i = 0; i < str.length(); i++) { char ch = str.charAt(i); if ((!(ch >= 'A' && ch <= 'Z')) && (!(ch >= 'a' && ch <= 'z'))) { return false; } } return true; } // Main method public static void main(String[] args) { // Checking for True case System.out.println("Test Case 1:"); String str1 = "GeeksforGeeks"; System.out.println("Input: " + str1); System.out.println("Output: " + isStringOnlyAlphabet(str1)); // Checking for String with numeric characters System.out.println("\nTest Case 2:"); String str2 = "Geeks4Geeks"; System.out.println("Input: " + str2); System.out.println("Output: " + isStringOnlyAlphabet(str2)); // Checking for null String System.out.println("\nTest Case 3:"); String str3 = null; System.out.println("Input: " + str3); System.out.println("Output: " + isStringOnlyAlphabet(str3)); // Checking for empty String System.out.println("\nTest Case 4:"); String str4 = ""; System.out.println("Input: " + str4); System.out.println("Output: " + isStringOnlyAlphabet(str4)); }} |
Test Case 1: Input: GeeksforGeeks Output: true Test Case 2: Input: Geeks4Geeks Output: false Test Case 3: Input: null Output: false Test Case 4: Input: Output: false
Check if a string contains only alphabets in Java using Lambda expression
Check if a string contains only alphabets in Java using Regex
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