Accept only letters

[EchoFool]

Hey,

 

Does any one know the regex to only allow the string to be letters only with no spaces/numbers/special characters?

 

Hope you can help as i use:

 

function textonly($Text){

return(preg_match('!^[^a-zA-Z]+$!', $Text));

}

 

$Name = SQLskip($_POST['name']);
$Name = str_replace(' ','', $Name);
$Name = strtolower($Name);
If(textonly($Name) != 1){
//BAD
}Else{
If(strlen($Name)>15 OR strlen($Name)<1){
//BAD
}Else{
//GOOD
  }
}

 

 

Yet some how it doesn't work as some one just managed to enter a blank name or it was a name with lots of spacebar presses i couldn't tell ... hope you can help

[Alex]

When possible you should avoid using the regex engine as it uses a lot of resources. In this case you should use ctype_alpha.

[EchoFool]

Thanks! Also i use a similiar thing to check a inputted number is not decimal and is integer is there a simpler function than:

//integer input check
function preg($Var){
If(!(preg_match('~^\d+$~', $Var))) {
   return(0);
   }Else{
   return($Var);
   }
}

[ignace]

What do you mean by is not decimal? not float? but is_integer?

[Daniel0]

What do you mean by is not decimal? not float? but is_integer?

 

is_int() checks if the data type is an integer. He is getting input from input from a user, so the data type will always be a string.

[litebearer]

Caution - Danger Old Man Thinking (NOT tested but...)

Psuedo Code:

$var_to_check = the variable you are check to see if it is (A) a valid number and (B) an integer

function Val_the_var($var_to_check) {
FIRST check if it is a valid number of any type ie int, float etc
 if (is_numeric ($val_to_check)) { 
	IF YES create a test variable to remove everything but the number 0-9
	$test_val_1 = preg_replace("/[^0-9]/","", $var_to_check);
	COMPARE the two values to see if they are the same
	IF($test_val_1 === $var_to_check) {
		IT IS a valid integer
		return a value of 2
	}else{
		IT IS A number BUT NOT an integer
		return a value of 1
} else { 
	IF NO
	return a value of zero
} 
}

$what_to_do = Val_the_var($var_to_check);

IF $what_to_do = 0  (meaning NOT a number) decide how you want to handle
IF $what_to_do = 1  (meaning a number BUT NOT an integer) decide how you want to handle
IF $what_to_do = 2  (meaning A VALID integer) decide how you want to handle

 

make sense?

 

[EchoFool]

What do you mean by is not decimal? not float? but is_integer?

 

is_int() checks if the data type is an integer. He is getting input from input from a user, so the data type will always be a string.

 

Does that mean is_int() will return false as the input is a string and not a number?

[Daniel0]

What do you mean by is not decimal? not float? but is_integer?

 

is_int() checks if the data type is an integer. He is getting input from input from a user, so the data type will always be a string.

 

Does that mean is_int() will return false as the input is a string and not a number?

 

Yes:

daniel@daniel-laptop:~$ php -r 'var_dump(is_int("123"));'
bool(false)

[EchoFool]

Hmm so i can't use is_int if 123 returns false then ... =/ id have to use my current preg_match ?

[Daniel0]

Yes, doing like this should be fine for checking if it's an integer:

 

if (preg_match('#^-?\d+$#', $theInteger)) {
    // is int
}

[EchoFool]

Oh your preg_match is different to mine, is that because mine is wrong or theres more than one way to do the same thing?

[Andy-H]

ctype_digit

is_numeric

[Daniel0]

Oh your preg_match is different to mine, is that because mine is wrong or theres more than one way to do the same thing?

 

The regex I provided allows negative integers.

 

ctype_digit

is_numeric

 

ctype_digit() doesn't allow negative integers. is_numeric() allows floats.

[EchoFool]

Okay so ctypt_digit seems the best function choice over preg_match

[niranjan81]

Or if negative integers are welcome as well

you can use validate integer flag while filtering the input, its nice, since its just then n there, not even a line more