<?php
  var_dump(strcmp("moo", "moo"));
  var_dump(strcmp("moo", "MOO"));
  var_dump(strcmp("mooO!", "mooo..."));
  var_dump(strcasecmp("MoOOoOOOo", "MooOoOooo"));
?>

int(0)
int(1)
int(-1)
int(0)