PHP子字符串不适用于整数[重复]

Question

This question already has an answer here:

• Zero-pad digits in string 3 answers
• Number with 0 on the front? [closed] 2 answers

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

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Answer 1

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);