Why is true output 1, but false but nothing output?

Why is true output 1, but false but nothing output it?

 
  
$a =true;


";

echo $a;

Echo '
';

$a =false;


";

echo $a;
?>

If it turns out to be 1 output, then the false should be converted to 0 output.
------Solution--------------------
According to its rules, this is programming.
------Solution--------------------
$a = false;
Var_dump ($a);

Output:
BOOL (FALSE)

Recommended for debugging with Var_dump ()
------Solution--------------------
That's what the author of the language wrote, and when you write a language so that false output 0,true nothing output, then someone asked why false output 0, and true nothing output it
------Solution--------------------
The Boolean value of PHP is true and false; echo true; 1 echo false No output content
PHP, like C, 0 means false; not 0 means true;

$a = 1;


";

echo $a;

Echo '
';

$a = 0;


";

echo $a;

------Solution--------------------
For numeric types, false is really 0, and for string, False is empty, although 0 of the number equals the null of the string, but it cannot be said that the bool conversion string is 0;

Var_dump ((int) false);
Var_dump ((string) false);

------Solution--------------------
Citation:

The author of the language wrote that, and when you write a language to let false output 0,true nothing output, then someone asked why false output 0, and true nothing output it

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