I want to check if a string contains a character repeated zero or more times, for example:
If my string is aaaaaa, bbbb, c or ***** it must return true.
If it contains aaab, cd, or **%*** it must return false.
In other words, if the string has 2 or more unique characters, it must return false.
How to go about this in PHP?
PS: Is there a way to do it without RegEx?
You could split on every character then count the array for unique values.
if(count(array_count_values(str_split('abaaaa'))) == 1) {
echo 'True';
} else {
echo 'false';
}
Demo: https://eval.in/760293
count(array_unique(explode('', string)) == 1) ? true : false;
You can use a regular expression with a back-reference:
if (preg_match('/^(.)\1*$/', $string)) {
echo "Same characters";
}
Or a simple loop:
$same = true;
$firstchar = $string[0];
for ($i = 1; $i < strlen($string); $i++) {
if ($string[$i] != $firstchar) {
$same = false;
break;
}
}
For the fun of it:
<?php
function str2Dec($string) {
$hexstr = unpack('H*', $string);
$hex = array_shift($hexstr);
return hexdec($hex);
}
function isBoring($string) {
return str2Dec($string) % str2Dec(substr($string, 0, 1)) === 0;
}
$string1 = 'tttttt';
$string2 = 'ttattt';
var_dump(isBoring($string1)); // => true
var_dump(isBoring($string2)); // => false
Obviously this works only in small strings because once it gets big enough, the INT will overflow and the mod will not produce the correct value. So, don't use this :) - posting it just to show a different idea from the usual ones.
strlen(str_replace($string[0], '', $string)) ? false : true;
You can check that the number of unique characters is greater than 1. This will perform well even if the input string is empty: (Demo)
$string = 'aaaba';
var_export(
strlen(count_chars($string, 3)) < 2 // false
);
Alternatively, you can trim the string by its first character, but this will generate warnings/notices if the input string has no length. (Demo)
$string = 'aaaba';
var_export(
!strlen(trim($string, $string[0])) // false
);
p.s. Yes, you could use !strlen(trim($string, #$string[0])) to prevent warnings/notices caused by a zero-length string, but I avoid error suppression like the plague because it generally gives code a bad smell.
Regex: ^(.)\1{1,}
^: Starting of string
(.): Match and capture single characted.
\1{1,}: using captured character one or more than once.
For this you can use regex
OR:
PHP code demo
$string="bbbb";
if($length=strlen($string))
{
substr_count($string,$string[0]);
if($length==substr_count($string,$string[0]))
{
echo "Do something";
}
}
I have a string that contains 2 informations (1.A Boolean/2.Something(could be number, letter, special chars and could be of any length)).
2 is a user input.
Exemples:
(part 1)"true".(part 2)"321654987" => "true321654987"
Could also be
"false321654987" or "trueweiufv2345fewv"
What I need is a way of parsing trought the string to check first if 1 is true (if its false do nothing), if it is true I need to check if to following part is a positive number higher than 0 (must accepte any number higher than 0 even decimal BUT not bin or hex (well... could be 10 but its would mean ten not two)).
Here is what I tried:
//This part is'nt important it work as it should....
if(isset($_POST['validate']) && $_POST['validate'] == "divSystemePositionnement")
{
$array = json_decode($_POST['array'], true);
foreach($array as $key=>$value)
{
switch($key)
{
case "txtFSPLongRuban":
//This is the important stuff HERE.....
if(preg_match('#^false.*$#', $value))//If false do nothing
{}
else if(!preg_match('#^true[1-9][0-9]*$#', $value))//Check if true and if number higher than 0.
{
//Do stuff,
//Some more stuff
//Just a bit more stuff...
//Done! No more stuff to do.
}
break;
//Many more cases...
}
}
}
As you can see I use regEx to parse trought to string. But it does'nt match decimal number.
I know how to do a regEx to parse decimal this is'nt the question.
The question is:
is there already a function in php that match the parsing I need?
If not, do any of you know a more efficient way to do the parsing or should I just add to my regEx the decimal part?
I was thinking something like :
test = str_split($value, "true")
if(isNumeric(test[1]) && test[1] > 0)
//problem is that isNumeric accepte hex and a cant have letter in there only straight out int or decimal number higher than 0.
Any idea??
Thank you so much for the help!
Use substr : documentation
if(substr($value, 0, 4) == "true"){
$number_part = substr($value, 5);
if(((int) $number == $number) || ((float) $number == $number)){
//do something...
}
}
You can do this:
case "txtFSPLongRuban":
if (preg_match('~^true(?=.*[^0.])([0-9]+(?:\.[0-9]+)?)$~', $value, $match))
{
// do what you want with $match[1] that contains the not null number.
}
break;
The lookahead (?=.*[^0.]) checks if there is somewhere a character that is not a 0 or a .
This oughta do the trick, and handle both types of values:
preg_match('/^(true|false)(.*)$/', $value, $matches);
$real_val = $matches[2];
if ($matches[1] == 'true') {
... true stuff ...
} else if ($matches[1] == 'false') {
... false stuff ...
} else {
... file not found stuff ...
}
Have a try with:
else if(!preg_match('#^true([1-9][0-9]*(?:\.[0-9]*)?$#', $value))
Have a look at ctype_digit:
Checks if all of the characters in the provided string, text, are numerical.
To check for decimals you can use filter_var:
if (filter_var('123.45', FILTER_VALIDATE_FLOAT) !== false) {
echo 'Number';
}
I am using the PHP filter_validate_int to perform a simple telephone validation. The length should be exactly 10 chars and all should be numeric. However as most of the telephone numbers start with a 0. The filter validate int function return false. Is there anyway to resolve this issue. Here is the code that I have used
if(!filter_var($value, FILTER_VALIDATE_INT) || strlen($value) != 10) return false;
There is nothing you can do to make this validation work. In any case, you should not be using FILTER_VALIDATE_INT because telephone numbers are not integers; they are strings of digits.
If you want to make sure that $tel is a string consisting of exactly 10 digits you can use a regular expression:
if (preg_match('/^\d{10}$/', $tel)) // it's valid
or (perhaps better) some oldschool string functions:
if (strlen($tel) == 10 && ctype_digit($tel)) // it's valid
Use preg_match
$str = '0123456789';
if(preg_match('/^\d{10}$/', $str))
{
echo "valid";
}
else
{
echo "invalid";
}
You can use regex :
if (!preg_match('~^\d{10}$~', $value)) return false;
It's a PHP bug - #43372
Regex are fine, but consume some resources.
This works fine with any integer, including zero and leading zeros
if (filter_var(ltrim($val, '0'), FILTER_VALIDATE_INT) || filter_var($val, FILTER_VALIDATE_INT) === 0) {
echo("Variable is an integer");
} else {
echo("Variable is not an integer");
}
0 is not a valid starting number for an int. 0 is the starting number of octal numbers.
A telephone number is a string, not an int. You have to use a regexp to validate it.
Probably you need to check whether the return is false or 0. The filters return the input when the validation is successful, or false when it fails.
Use strict comparison (=== or !==) for the comparison, like $result!==false.
if(filter_var($squid, FILTER_VALIDATE_INT)!==false ) {
//if it's here, it passed validation
}
You could also use the is_numeric function:
http://php.net/manual/en/function.is-numeric.php
If I have two PHP variables that are strings and one is a multi-word string while the other is a single-word string.
How can I write a custom function that returns true if the larger string contains the smaller string.
Here is what I have so far in terms of code:
function contains($smaller, $larger){
//if $smaller is in larger{
return true;
}
else{
return false;
}
How can I do the commented out part?
I can't use a regex since I don't know the exact value of $smaller, right?
This version should return a Boolean and guard against 0 vs false return
function contains($smaller, $larger){
return strpos($larger, $smaller) !== false;
}
There is a php function strstr which will return the position of the "smaller" string.
http://www.php.net/manual/en/function.strstr.php
if(strstr($smaller, $larger))
{
//Its true
}
PHP already has it. Strpos is your answer
http://php.net/manual/en/function.strrpos.php
if (strpos($larger, $smaller) !== false){
// smaller string is in larger
} else {
// does not contains
}
If it founds the string, it returns the position. Beware to check for 0 (if the position of a smaller is in the 0-th location)
I want to convert these types of values, '3', '2.34', '0.234343', etc. to a number. In JavaScript we can use Number(), but is there any similar method available in PHP?
Input Output
'2' 2
'2.34' 2.34
'0.3454545' 0.3454545
You don't typically need to do this, since PHP will coerce the type for you in most circumstances. For situations where you do want to explicitly convert the type, cast it:
$num = "3.14";
$int = (int)$num;
$float = (float)$num;
There are a few ways to do so:
Cast the strings to numeric primitive data types:
$num = (int) "10";
$num = (double) "10.12"; // same as (float) "10.12";
Perform math operations on the strings:
$num = "10" + 1;
$num = floor("10.1");
Use intval() or floatval():
$num = intval("10");
$num = floatval("10.1");
Use settype().
To avoid problems try intval($var). Some examples:
<?php
echo intval(42); // 42
echo intval(4.2); // 4
echo intval('42'); // 42
echo intval('+42'); // 42
echo intval('-42'); // -42
echo intval(042); // 34 (octal as starts with zero)
echo intval('042'); // 42
echo intval(1e10); // 1410065408
echo intval('1e10'); // 1
echo intval(0x1A); // 26 (hex as starts with 0x)
echo intval(42000000); // 42000000
echo intval(420000000000000000000); // 0
echo intval('420000000000000000000'); // 2147483647
echo intval(42, 8); // 42
echo intval('42', 8); // 34
echo intval(array()); // 0
echo intval(array('foo', 'bar')); // 1
?>
In whatever (loosely-typed) language you can always cast a string to a number by adding a zero to it.
However, there is very little sense in this as PHP will do it automatically at the time of using this variable, and it will be cast to a string anyway at the time of output.
Note that you may wish to keep dotted numbers as strings, because after casting to float it may be changed unpredictably, due to float numbers' nature.
Instead of having to choose whether to convert the string to int or float, you can simply add a 0 to it, and PHP will automatically convert the result to a numeric type.
// Being sure the string is actually a number
if (is_numeric($string))
$number = $string + 0;
else // Let the number be 0 if the string is not a number
$number = 0;
Yes, there is a similar method in PHP, but it is so little known that you will rarely hear about it. It is an arithmetic operator called "identity", as described here:
Aritmetic Operators
To convert a numeric string to a number, do as follows:
$a = +$a;
If you want get a float for $value = '0.4', but int for $value = '4', you can write:
$number = ($value == (int) $value) ? (int) $value : (float) $value;
It is little bit dirty, but it works.
You can use:
(int)(your value);
Or you can use:
intval(string)
In PHP you can use intval(string) or floatval(string) functions to convert strings to numbers.
You can always add zero to it!
Input Output
'2' + 0 2 (int)
'2.34' + 0 2.34 (float)
'0.3454545' + 0 0.3454545 (float)
Just a little note to the answers that can be useful and safer in some cases.
You may want to check if the string actually contains a valid numeric value first and only then convert it to a numeric type (for example if you have to manipulate data coming from a db that converts ints to strings). You can use is_numeric() and then floatval():
$a = "whatever"; // any variable
if (is_numeric($a))
var_dump(floatval($a)); // type is float
else
var_dump($a); // any type
Here is the function that achieves what you are looking for. First we check if the value can be understood as a number, if so we turn it into an int and a float. If the int and float are the same (e.g., 5 == 5.0) then we return the int value. If the int and float are not the same (e.g., 5 != 5.3) then we assume you need the precision of the float and return that value. If the value isn't numeric we throw a warning and return null.
function toNumber($val) {
if (is_numeric($val)) {
$int = (int)$val;
$float = (float)$val;
$val = ($int == $float) ? $int : $float;
return $val;
} else {
trigger_error("Cannot cast $val to a number", E_USER_WARNING);
return null;
}
}
If you want the numerical value of a string and you don't want to convert it to float/int because you're not sure, this trick will convert it to the proper type:
function get_numeric($val) {
if (is_numeric($val)) {
return $val + 0;
}
return 0;
}
Example:
<?php
get_numeric('3'); // int(3)
get_numeric('1.2'); // float(1.2)
get_numeric('3.0'); // float(3)
?>
Source: https://www.php.net/manual/en/function.is-numeric.php#107326
I've been reading through answers and didn't see anybody mention the biggest caveat in PHP's number conversion.
The most upvoted answer suggests doing the following:
$str = "3.14"
$intstr = (int)$str // now it's a number equal to 3
That's brilliant. PHP does direct casting. But what if we did the following?
$str = "3.14is_trash"
$intstr = (int)$str
Does PHP consider such conversions valid?
Apparently yes.
PHP reads the string until it finds first non-numerical character for the required type. Meaning that for integers, numerical characters are [0-9]. As a result, it reads 3, since it's in [0-9] character range, it continues reading. Reads . and stops there since it's not in [0-9] range.
Same would happen if you were to cast to float or double. PHP would read 3, then ., then 1, then 4, and would stop at i since it's not valid float numeric character.
As a result, "million" >= 1000000 evaluates to false, but "1000000million" >= 1000000 evaluates to true.
See also:
https://www.php.net/manual/en/language.operators.comparison.php how conversions are done while comparing
https://www.php.net/manual/en/language.types.string.php#language.types.string.conversion how strings are converted to respective numbers
In addition to Boykodev's answer I suggest this:
Input Output
'2' * 1 2 (int)
'2.34' * 1 2.34 (float)
'0.3454545' * 1 0.3454545 (float)
Only multiply the number by 1 so that the string is converted to type number.
//String value
$string = "5.1"
if(is_numeric($string)){
$numeric_string = $string*1;
}
Alright so I just ran into this issue. My problem is that the numbers/strings in question having varying numbers of digits. Some have no decimals, others have several. So for me, using int, float, double, intval, or floatval all gave me different results depending on the number.
So, simple solution... divide the string by 1 server-side. This forces it to a number and retains all digits while trimming unnecessary 0's. It's not pretty, but it works.
"your number string" / 1
Input Output
"17" 17
"84.874" 84.874
".00234" .00234
".123000" .123
"032" 32
Here is a function I wrote to simplify things for myself:
It also returns shorthand versions of boolean, integer, double and real.
function type($mixed, $parseNumeric = false)
{
if ($parseNumeric && is_numeric($mixed)) {
//Set type to relevant numeric format
$mixed += 0;
}
$t = gettype($mixed);
switch($t) {
case 'boolean': return 'bool'; //shorthand
case 'integer': return 'int'; //shorthand
case 'double': case 'real': return 'float'; //equivalent for all intents and purposes
default: return $t;
}
}
Calling type with parseNumeric set to true will convert numeric strings before checking type.
Thus:
type("5", true) will return int
type("3.7", true) will return float
type("500") will return string
Just be careful since this is a kind of false checking method and your actual variable will still be a string. You will need to convert the actual variable to the correct type if needed. I just needed it to check if the database should load an item id or alias, thus not having any unexpected effects since it will be parsed as string at run time anyway.
Edit
If you would like to detect if objects are functions add this case to the switch:
case 'object': return is_callable($mixed)?'function':'object';
$a = "10";
$b = (int)$a;
You can use this to convert a string to an int in PHP.
I've found that in JavaScript a simple way to convert a string to a number is to multiply it by 1. It resolves the concatenation problem, because the "+" symbol has multiple uses in JavaScript, while the "*" symbol is purely for mathematical multiplication.
Based on what I've seen here regarding PHP automatically being willing to interpret a digit-containing string as a number (and the comments about adding, since in PHP the "+" is purely for mathematical addition), this multiply trick works just fine for PHP, also.
I have tested it, and it does work... Although depending on how you acquired the string, you might want to apply the trim() function to it, before multiplying by 1.
Late to the party, but here is another approach:
function cast_to_number($input) {
if(is_float($input) || is_int($input)) {
return $input;
}
if(!is_string($input)) {
return false;
}
if(preg_match('/^-?\d+$/', $input)) {
return intval($input);
}
if(preg_match('/^-?\d+\.\d+$/', $input)) {
return floatval($input);
}
return false;
}
cast_to_number('123.45'); // (float) 123.45
cast_to_number('-123.45'); // (float) -123.45
cast_to_number('123'); // (int) 123
cast_to_number('-123'); // (int) -123
cast_to_number('foo 123 bar'); // false
function convert_to_number($number) {
return is_numeric($number) ? ($number + 0) : FALSE;
}
You can use:
((int) $var) ( but in big number it return 2147483647 :-) )
But the best solution is to use:
if (is_numeric($var))
$var = (isset($var)) ? $var : 0;
else
$var = 0;
Or
if (is_numeric($var))
$var = (trim($var) == '') ? 0 : $var;
else
$var = 0;
Simply you can write like this:
<?php
$data = ["1","2","3","4","5"];
echo json_encode($data, JSON_NUMERIC_CHECK);
?>
There is a way:
$value = json_decode(json_encode($value, JSON_NUMERIC_CHECK|JSON_PRESERVE_ZERO_FRACTION|JSON_UNESCAPED_SLASHES), true);
Using is_* won't work, since the variable is a: string.
Using the combination of json_encode() and then json_decode() it's converted to it's "true" form. If it's a true string then it would output wrong.
$num = "Me";
$int = (int)$num;
$float = (float)$num;
var_dump($num, $int, $float);
Will output: string(2) "Me" int(0) float(0)
Now we are in an era where strict/strong typing has a greater sense of importance in PHP, I use json_decode:
$num = json_decode('123');
var_dump($num); // outputs int(123)
$num = json_decode('123.45');
var_dump($num); // outputs float(123.45)
You can change the data type as follows
$number = "1.234";
echo gettype ($number) . "\n"; //Returns string
settype($number , "float");
echo gettype ($number) . "\n"; //Returns float
For historical reasons "double" is returned in case of a float.
PHP Documentation
If you don't know in advance if you have a float or an integer,
and if the string may contain special characters (like space, €, etc),
and if it may contain more than 1 dot or comma,
you may use this function:
// This function strip spaces and other characters from a string and return a number.
// It works for integer and float.
// It expect decimal delimiter to be either a '.' or ','
// Note: everything after an eventual 2nd decimal delimiter will be removed.
function stringToNumber($string) {
// return 0 if the string contains no number at all or is not a string:
if (!is_string($string) || !preg_match('/\d/', $string)) {
return 0;
}
// Replace all ',' with '.':
$workingString = str_replace(',', '.', $string);
// Keep only number and '.':
$workingString = preg_replace("/[^0-9.]+/", "", $workingString);
// Split the integer part and the decimal part,
// (and eventually a third part if there are more
// than 1 decimal delimiter in the string):
$explodedString = explode('.', $workingString, 3);
if ($explodedString[0] === '') {
// No number was present before the first decimal delimiter,
// so we assume it was meant to be a 0:
$explodedString[0] = '0';
}
if (sizeof($explodedString) === 1) {
// No decimal delimiter was present in the string,
// create a string representing an integer:
$workingString = $explodedString[0];
} else {
// A decimal delimiter was present,
// create a string representing a float:
$workingString = $explodedString[0] . '.' . $explodedString[1];
}
// Create a number from this now non-ambiguous string:
$number = $workingString * 1;
return $number;
}
All suggestions lose the numeric type.
This seems to me a best practice:
function str2num($s){
// Returns a num or FALSE
$return_value = !is_numeric($s) ? false : (intval($s)==floatval($s)) ? intval($s) :floatval($s);
print "\nret=$return_value type=".gettype($return_value)."\n";
}
//Get Only number from string
$string = "123 Hello Zahid";
$res = preg_replace("/[^0-9]/", "", $string);
echo $res."<br>";
//Result 123