strpbrk method
Finds the first character in the string str1 that matches any character specified in str2.
Returns the index of the character, or -1 if no such character exists.
Implementation
int strpbrk(String str1, String str2) {
for (int i = 0; i < str1.length; i++) {
if (str2.contains(str1[i])) {
return i;
}
}
return -1;
}