在PHP中为什么是真正的转换1和false转换为空字符串？

A boolean TRUE value is converted to the string "1". Boolean FALSE is converted to "" (the empty string).

Why isn't FALSE cast to "0"?

If you cast to an int, then to a string, it prints 0's..

$x=false;
print (string)(int)$x;

Prints 0. You can, of course, omit the string type cast as it's done by print anyway.