Numbers only

[Woodburn2006]

How do you determine that na input should only be numbers?

 

for example i ise this line do check the stringlength of an input:

if(strlen($year) != 4){$error[] = "year";}

 

how would i use that to check if the input is just numbers?

[MmmVomit]

There are several different ways to do that.  ctype_digit($year) will do what you want.

 

This might also be a good time to play around with regular expressions.  preg_match('/^[0-9]*$/', $year) will also do the same thing.

[php_dave]

Hey,

 

This should work

 

preg_match("/^[0-9]+$/", $year);

 

 

Edit - Cross post!

 

[recklessgeneral]

I'll add a bit to the other regular expressions. This one restricts the length to 4 characters and makes it more year like by restricting the range of the first digit to 1 or 2:

 

preg_match("/^[1-2][0-9]{3}$/", $year);

[MmmVomit]

Yes, my regex-fu is still very weak.

[Woodburn2006]

in what way would i use this?

im new to the php game

 

i put it as this but when i put in a valid date i get the error

 

if(preg_match("/^[1-2][0-9]{3}$/", $year)){$error[] = "year";}

[MmmVomit]

Just add in a logical not.

 

preg_match($regex, $string) returns a boolean.  You can think of $regex as a set of rules that a string has to follow. 

 

In this case '/^[1-2][0-9]{3}$/' means "Starts with a one or two and is followed by three digits."  If $string follows all the rules, preg_match returns true.