Date: 2010aug31
Update: 2025sep29
Language: Java
Keywords: hex
Q. Java: Test if a string is all hexadecimal characters
A. There are many ways but I think the nicest is using Pattern's {XDigit}
As shown in this full example:
class Demo {
static boolean isAllHex(final String s) {
return s.matches("\\p{XDigit}+");
}
public static final void main(String []args) {
{
var str = "12345";
System.out.println("is '" + str + "' all hex=" + isAllHex(str));
}
{
var str = "abcdef";
System.out.println("is '" + str + "' all hex=" + isAllHex(str));
}
{
var str = "abcdefg";
System.out.println("is '" + str + "' all hex=" + isAllHex(str));
}
}
}
Output:
is '12345' all hex=true
is 'abcdef' all hex=true
is 'abcdefg' all hex=false