would not output anything since you did not tell it to (just being picky there)
<?php
$var = 1; // Will Turn out true
echo "$var" ;
$var2 = -1; // False
echo "$var2" ;
$var3 = abs((int) $var2);
echo "$var3" ;
// Will return false and will be turned into positive ( i believe, feel free to tell me otherwise )
?>
$var1 would show "1"
$var2 = "-1"
$var3 = 1
all 3 on the same line since i just just echo 3 times not telling it to go on a new line