PHP子字符串不适用于整数[重复]

I am trying to extract part of a number using sustr() but the following is not working:

$num = 012014;

echo substr($num, 0,2);

returns 51

BUT

$num = '012014';

echo substr($num, 0,2);

returns 01

I want it to return 01 can someone help me

</div>

Is is not a normal number, when it's prepended with a zero (0). Then it's an octal number

If you treat $num as a string, it'll work.

$num = '012014';
echo substr($num, 0,2);

Ooops I didn't notice the leading zero. You should just define $num as a string

$num = '0123';

I guess you must declare the variable as string like this.

$num = '012014'; 
echo substr( (string)$num, 0, 2 );

Please try this

$num = 123424;
$num = (string)$num;

echo substr($num, 0,2);