$reg1 = preg_match("/[0-9]/", "String to check"); // Only numbers
$reg2 = preg_match("/[a-z]/i", "String to check"); // Only letters
$reg3 = preg_match("/[a-z0-9-._]/i", "String to check"); // numbers, letters and -._
There are a few different ways to use those regular expressions but I laid out a simple preg_match function stored in each variable above.
Last edited by Sup3rkirby; 11-14-2012 at 01:53 AM.
"Given billions of tries, could a spilled bottle of ink ever fall into the words of Shakespeare?"
Those checks are all well and good, if all you want to know if is the string contains "a letter" , "a number" or "a letter, number, hyphen, period, or underscore".
I'm going to assume this is for validating some type of login or password?
If that's the case, you probably want to check for things OTHER than what you want.
Take a look at these examples:
PHP Code:
$test_string = "Str1ng-t0_ch3ck.";
$test_string_words = "Stringtocheck";
$test_string_numbers = "12345";
$test_string_mixed = "Str1ng t0 ch3ck."; // note the added spaces; need to add \s to the regex patterns to match this
$reg1 = preg_match("/[^0-9]/", $test_string); // Only numbers
$reg1a = preg_match("/[^0-9]/", $test_string_numbers); // Only numbers
$reg2 = preg_match("/[^a-z]/i", $test_string); // Only letters
$reg2a = preg_match("/[^a-z]/i", $test_string_words); // Only letters
$reg3 = preg_match("/[^a-z0-9-._]/i", $test_string); // numbers, letters and -._
$reg4 = preg_match("/[^\w-._]/i", $test_string_mixed); // numbers, letters and -._
/*
preg_match returns int(1) if it finds a match to the pattern or int(0) if it does not find a match.
since these checks are checking for NOT IN THE PATTERN, then (if $var === 0) "passes" the regex and (if $var === 1) "fails"
{three "equal signs" matches exactly the type int()}
------------ reg1 (it found something other than just numbers)
1
------------
------------ reg1a (it found only numbers)
0
------------
------------ reg2 (it found something other than just letters)
1
------------
------------ reg2a (it found only letters)
0
------------
------------ reg3 (it found only the acceptable characters)
0
------------
------------ reg4 (condensed "word boundries (letter and numbers) plus the `extra characters`")
1
------------
Also, please see the various ctype_*() functions for more efficient ways to do certain checks.
"Please give us a simple answer, so that we don't have to think, because if we think, we might find answers that don't fit the way we want the world to be."
~ Terry Pratchett in Nation
i want check input and
1.if it was just numbers return 1 and if it has characters return 0.
2.if it was just characters return 1 and if it has numbers return 0.
3.if it was just characters and numbers return 1 and if it has else characters line &,*,... return 0.
3.if it was just characters and numbers and -_. return 1 and if it has else characters line &,*,... return 0.
Some Regular expresstion
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