为什么加号不能输出？

Question

<?php
    $hu_new=12345;
    $hu_old=11111;
    printf("%7.2f %c%.2f<br>",$hu_new/100,($hu_new>$hu_old)?"+":"-",($hu_new-$hu_old)/100);
    $hu_new=12345;
    $hu_old=13333;
    printf("%7.2f %c%.2f<br>",$hu_new/100,($hu_new>$hu_old)?"+":"-",($hu_new-$hu_old)/100);
?>
也是一样!

Answer 1

    $hu_new=12345;
    $hu_old=11111;
    printf("%7.2f %s%.2f<br>",$hu_new/100,($hu_new>$hu_old)?"+":"",($hu_new-$hu_old)/100);
    $hu_new=12345;
    $hu_old=13333;
    printf("%7.2f %s%.2f<br>",$hu_new/100,($hu_new>$hu_old)?"+":"",($hu_new-$hu_old)/100);