PHP Sadness

Ternary operator associativity

The ternary operator is left-associative and therefore behaves entirely incorrectly:

$ cat ternary.php
<?php
echo (FALSE ? "a" : FALSE ? "b" : "c")."\n";
echo (FALSE ? "a" : TRUE ? "b" : "c")."\n";
echo (TRUE ? "a" : FALSE ? "b" : "c")."\n";
echo (TRUE ? "a" : TRUE ? "b" : "c")."\n";
?>

$ php ternary.php
c
b
b
b

In any other language with a ternary operator, you can stack them and build an if-elseif-elseif-else expression:

$ cat ternary.pl
#!/usr/bin/perl -w
use strict;

print +(0 ? "a" : 0 ? "b" : "c")."\n";
print +(0 ? "a" : 1 ? "b" : "c")."\n";
print +(1 ? "a" : 0 ? "b" : "c")."\n";
print +(1 ? "a" : 1 ? "b" : "c")."\n";

$ perl ternary.pl
c
b
a
a

$ cat ternary.c
#include <stdio.h>

int main() {
  printf("%s\n", 0 ? "a" : 0 ? "b" : "c");
  printf("%s\n", 0 ? "a" : 1 ? "b" : "c");
  printf("%s\n", 1 ? "a" : 0 ? "b" : "c");
  printf("%s\n", 1 ? "a" : 1 ? "b" : "c");
}

$ gcc -o ternary ternary.c; ./ternary
c
b
a
a