[Resolved] Vaildate textfield

[kcgame]

Hi,

I'm having problems to vaildate a textfield. As i only accept numeric data from the field, i would like to output an error if user input letters or nothing is written in the field.

if(isset($_POST[button])) {

if(!$textfield){
echo"The field only accepts numeric numbers";
} else {

 //process the data
}


}

How can i modify the IF condition to enable it to check for letters?
Any help is appreciated.Thanks🙂

[Huuggee]

there are a set of ctype functions for this

ctype_digit($string)

if(isset($_POST[button])) {

if(!$textfield || !ctype_digit($textfield)){
echo"The field only accepts numeric numbers";
} else {

 //process the data
} 
}

[laserlight]

A little more accurately, assuming your textfield is named "textfield":

if (isset($_POST['button'])) {
	if (empty($_POST['textfield']) || !ctype_digit($_POST['textfield'])){
		echo "The field only accepts numeric characters";
	} else {
		//process the data
	}
}

NB: 2**12=4096 => Yay, the post that brings me past 12 bits!

[Huuggee]

just as a warning, however, ctype_digit()
will return false if there is a decimal anywhere in the number, as the type of that character is not numeric

[Drakla]

if you want to allow the use of floating point numbers then you'll have to use is_numeric instead of ctype_digit.

And remember ctype works only on strings, which will be fine for your form

ctype_digit('12') is true
ctype_digit(12) is false

This is the complete opposite behaviour to is_int

is_numeric doesn't give a monkeys

[kcgame]

Thanks for the help😃

ctype_digit works fine in my code as i only interested in integer value.

One question thou, how different is it between;

!$POST['textfield'] and
empty($POST['textfield'])

[laserlight]

One question thou, how different is it between;

!$POST['textfield'] and
empty($POST['textfield'])

Use [man]empty/man when the incoming variable concerned may not exist.