How to override/change the default removal of leading zeroes by PHP substr() function?

Question

In PHP when we do a substr() such that the resultant string should be something like 0004, PHP automatically removes the leading 0s and just gives 4.

I want to avoid this behavior. I want the leading zeroes to stay there. How can I enforce that?

Forexample the following snippet prints 4.

echo substr("100041", 1, 4); 

How can I force it to print 0004?

Answer 1

Who said? Php doesn't remove 0 in string...