Posted Apr 19, 2012 14:43 UTC (Thu) by anselm
In reply to: Not Again
Parent article: PHP: a fractal of bad design (fuzzy notepad)
»Implementation-defined« means that there are various options out of which the implementation needs to pick one and adhere to it. For example, an implementation can set the size of »short« arbitrarily (as long as it is not smaller than that of »char« and not larger than that of »int«) but the choice, whatever it turns out to be, must be consistently enforced.
With undefined behaviour the implementation can do anything it wants and doesn't have to do the same thing twice even in the same situation.
to post comments)