Ternary Operator

ALL HAIL!

About two or three days ago someone started a thread about a website called javabat.com where a user could solve small Java exercises in order to learn the language.

I have decided to swing on some of these exercises with nested ternary operations and finals.

public final boolean posNeg(final int a, final int b, final boolean negative) {
 return negative ? a < 0 && b < 0 : a < 0 && b > 0 || a > 0 && b < 0;
}

public final int strCount(final String str, final String sub) {
 return str.length() == 0 ? 0 : str.startsWith(sub) ? 1 + strCount(str.substring(sub.length()),sub) : strCount(str.substring(1),sub);
}

public final int count11(final String str) {
 return str.length() == 0 ? 0 : str.startsWith("11") ? 1 + count11(str.substring(2)) : count11(str.substring(1));
}

public final int countAbc(final String str) {
 return str.length() < 3 ? 0 : str.startsWith("abc") || str.startsWith("aba") ? 1 + countAbc(str.substring(1)) : countAbc(str.substring(1));
}

public final int countX(final String str) {
 return (str.length() == 0) ? 0 : (str.startsWith("x")) ? 1 + countX(str.substring(1)) : countX(str.substring(1));
}

public final int redTicket(final int a, final int b, final int c) {
 return a + b + c == 6 ? 10 : a == b && a == c && b == c ? 5 : a != b && c != a ? 1 : 0;
}

public final int blackjack(int a, int b) {
 if (b > a) { b ^= a; a ^= b; b ^= a; }
 return a > 21 ? b > 21 ? 0 : b : a;
}

public final int luckySum(final int a,final int b,final int c) {
 return a == 13 ? 0 : b == 13 ? a : c == 13 ? a + b : a + b + c;
}

public final int intMax(final int a, final int b,final int c) {
 return a > b ? a > c ? a : c : b > c ? b : c;
}

public final int max1020(int a,int b) {
 if (b > a) { b ^= a; a ^= b; b ^= a; }
 return inRange(a) ? a : inRange(b) ? b : 0;
}

private final boolean inRange(final int n) {
 return n >= 10 && n <= 20;
}

public final String endUp(final String str) {
  int bounds = str.length() - 3;
  return str.length() < 4 ? str.toUpperCase() : str.substring(0,bounds) + str.substring(bounds).toUpperCase();
}

public final int caughtSpeeding(int speed, final boolean isBirthday) {
 if (isBirthday) speed -= 5;
 return speed <= 60 ? 0 : speed >= 61 && speed <= 80 ? 1 : 2;
}

public final int dateFashion(final int you, final int date) {
 return you <= 2 || date <= 2 ? 0 : you >= 8 || date >= 8 ? 2 : 1;
}