I want to validate that a string consists of numbers or commas or semicolons:
valid: 1.234
valid: 1,234
invalid: 1.23a
invalid: 1.2_4
What works:
use str_split to create an array out of the string and use in_array with array(0,1,2,3,4,5,6,7,8,9,',',';').
But this feels circuitous to me and since I have to do this with millions of strings I want to make sure there is no more efficient way.
Question: Is there a more efficient way?
If you only need to validate a string (not sanitize or modify it), you can use regex. Try the following:
if (preg_match('/^[0-9\,\;\.]+$/', $string)) {
// ok
} else {
// not ok
}
false("not ok") for the input 1.234. While the OP expects it to be valid: valid: 1.234 valid: 1,234 invalid: 1.23a invalid: 1.2_4
The solution using preg_match function:
// using regexp for (numbers OR commas OR semicolons) - as you've required
function isValid($str) {
return (bool) preg_match("/^([0-9.]|,|;)+$/", $str);
}
var_dump(isValid("1.234")); // bool(true)
var_dump(isValid("1.23a")); // bool(false)
var_dump(isValid("1,234")); // bool(true)
preg_match()is likely to perform better than matching the whole string. In other words, stop searching the string as soon as a character that is not in your white list is found in the string.