leading zero not allowed, regex

[CrustyDOD]

Hey

 

I want to show error when the input in field contains leading zero. Field should be integer and nothing else!

So for example, this types are not allowed:

- 0

- 00

- 01

- 094

and so on..

 

so far, i have this: eregi('^([0-9]{1,10})$', $d)..

 

Field must contain ONLY integers but do not allow leading zero!

 

Anyone can help?

[Wildbug]

There are a number of ways to accomplish this.  If you don't have to use regular expressions, which is preferred due to (albeit minor) performance considerations, you can use ltrim($var,'0') to trim zeros from the left side (beginning) of the string.  You can use substr($var,0,1) == 0 to check if the first character is a zero.  If you are accepting user input, you'll have to check for other things, of course, like leading/trailing whitespace.

 

But a regex that will check for an integer sans leading zero(s):

 

preg_match('/^([1-9]\d*)/',$var,$match);
echo $match[1];

 

That pattern matches one digit from one through nine (not zero) at the beginning of the string, followed by none or some numeric digits.  You can constrain the amount of excess digits by changing the asterisk to {,10} for instance.  You can also leave off the caret (^) in case of leading whitespace, again, if you are accepting user input.

[CrustyDOD]

Almost forgot about this

 

Right, maybe i wrote this in the wrong way. 0 is allowed to be after the first digit!

- 20

- 200162100

and so on..

 

All i want is that 0 is not in the first place but it can be anywhere else.

 

Yeah i know about other options i can use but if possible i would like to do this with regex..

[Wildbug]

All i want is that 0 is not in the first place but it can be anywhere else.

 

Yes, the previous pattern DOES that.

[neel_basu]

I think Its simple

^[^0]