Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Is it possible to check if a String only contains ASCII in java?
Using regular expression
You can find whether a particular String value contains ASCII characters using the following regular expression −
\A\p{ASCII}*\zThe matches() method of the String class accepts a regular expression and verifies whether the current string matches the given expression if so, it returns true, else it returns false.
Therefore, Invoke the matches() method on the input/required string by passing the above specified regular expression as a parameter.
Example
import java.util.Scanner;
public class OnlyASCII {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter a string value: ");
String input = sc.nextLine();
//Verifying for ACCII
boolean result = input.matches("\A\p{ASCII}*\z");
if(result) {
System.out.println("String approved");
} else {
System.out.println("Contains non-ASCII values");
}
}
}Output1
Enter a string value: hello how are you String approved
Output2
Enter a string value: whÿ do we fall Contains non-ASCII values
Verifying each character
If you convert ASCII characters to integers all the results will be less than or equal to 127.
The charAt() method of the String class accepts an integer value and returns the character at specified index.
Using this method retrieve each character in the given String and verify whether they are greater than 127.
Example
import java.util.Scanner;
public class OnlyASCII {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter a string value: ");
String input =sc.next();
//Converting given string to character array
char charArray[] = input.toCharArray();
boolean result = true;
for(int i = 0; i < input.length(); i++) {
int test = (int)input.charAt(i);
if (test<=127) {
result = true;
}else if (test >127){
result = false;
}
}
System.out.println(result);
if(result) {
System.out.println("String approved");
}else {
System.out.println("Contains non-ASCII values");
}
}
}Output1
Enter a string value: whÿ false Contains non-ASCII values
Output2
Enter a string value: hello true String approved
1K+ Views
