So I'm attempting to concatenate two integers that form a whole serial number to verify if a user has the correct serial code. My second variable will always begin with P, how would I ignore the P from a user input while still having it appear in the concatenated variables in a function like this?
$a = '1800';
$b = P100000000;
if ($a >= "1800" && $b >= "100000000") {
echo "$a-$b is correct";
} else {
echo "I'm sorry, that serial does not match our system.";
}
One way is to use ltrim.
if ($a >= "1800" && ltrim($b, 'P') >= "100000000") { ...
If the P isn't there for some reason, it won't remove anything.
Another way to remove all non-numeric characters from a string and convert it to an integer for comparison would be something like:
intval( filter_var( $b, FILTER_SANITIZE_NUMBER_INT ) )
the filter_var function returns a string, and the intval function returns the integer value from a string.
<?php
$a = 1800; // no quotes here for a number
$b = 'P100000000'; // quotes here please
$real_b = (int)substr($b,1); // cut the first letter, then cast to int
if ($a >= 1800 && $real_b >= 100000000) { // no quotes here for numbers or its a string
echo "$a-$b is correct";
} else {
echo "I'm sorry, that serial does not match our system.";
}
Could also use regex if you have multiple non-digit beginning character;
<?php
$a = '1800';
$b = P100000000;
$b = preg_replace('/^\D/', '', $b);
print("${b}\n");
I want to XOR two strings (hex-encoded) in php.
I have tried using operator ^, but I get only 0.
How can I do that? Why is it wrong?
<?php
$s1 = 'ABCDEF1234567890';
$s2 = '0987654321ABCDEF';
$x = bin2hex(pack('H*',$s1) ^ pack('H*',$s2));
?>
$x = dechex(hexdec($s1) ^ hexdec($s2));
http://codepad.org/fgRfAPAI
The problem, that you initially had is, that a hex-string is in fact a string. When you use binary operators on strings, it uses the character-codes as byte value.
You need to decode them with hex2bin() before you apply the XOR ^ operator.
Update: I always forget that this function requires PHP/5.4 or greater, which can be an issue. In such case, you need to use the not very intuitive pack() function:
$binary = pack('H*', $hexadecimal);
Based on #KingCrunch's answer here and the comments I wrote this simple loop to compare octets and build up the answer. Interestingly, this has the same result as #lawlor's answer.
$key1 = 'ABCDEF1234567890ABCDEF1234567890';
$key2 = '0987654321ABCDEF0987654321ABCDEF';
$key1_octets = str_split($key1, 2);
$key2_octets = str_split($key2, 2);
$xor = '';
foreach ($key1_octets as $id => $key1_octet) {
$xor .= dechex(hexdec($key1_octets[$id]) ^ hexdec($key2_octets[$id]));
}
print $xor;
print bin2hex(pack('H*',$key1) ^ pack('H*',$key2));
I'm not actually sure if either one is a valid result, but I put this forth for feedback and in case it helps someone else who is looking at #KingCrunch's answer without knowing how to deal with the octets.
I'm trying to check if a variable has more than one zero. It seems php treats multiple zeros as one zero. For example, the following code always returns true no matter how many zeros the variable has:
$input = 0000;//or "0000"
if($input==00) echo "true";
else echo "false";
My question is : How can I make the above code return true only if it has the exact number of zero in the if statement? Thanks
How can I make the above code return true only if it has the exact number of zero in the if statement?
Use strings.
Integers is the only data of the number, not its presentation. So 0000 equals to 0.
Currently, your $input is a decimal integer. Therefore, 0 does in fact equal 00000.
You need to define it as a string and then compare with other strings.
$input = "0000";
if( $input === "00" ) { echo "yes"; } else { echo "no"; }
Use strings instead of numbers
$input = "00000";
// This searches for 0 extra zeros on the left
if(strpos($input,"0")==0 && $input!=="0"){
echo "true";
}
else{
echo "false";
}
<?php
$input = "0000";
if(strcmp($input,"0000")==0) {echo "they match";}
else {echo "They dont";}
?>
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
In PHP 5, I use intval() whenever I get numbers as an input. This way, I want to ensure that I get no strings or floating numbers. My input numbers should all be in whole numbers. But when I get numbers >= 2147483647, the signed integer limit is crossed.
What can I do to have an intval() equivalent for numbers in all sizes?
Here's what I want to have:
<?php
$inputNumber = 3147483647.37;
$intNumber = intvalEquivalent($inputNumber);
echo $intNumber; // output: 3147483647
?>
Thank you very much in advance!
Edit: Based on some answers, I've tried to code an equivalent function. But it doesn't work exactly as intval() does yet. How can I improve it? What is wrong with it?
function intval2($text) {
$text = trim($text);
$result = ctype_digit($text);
if ($result == TRUE) {
return $text;
}
else {
$newText = sprintf('%.0f', $text);
$result = ctype_digit($newText);
if ($result == TRUE) {
return $newText;
}
else {
return 0;
}
}
}
Try this function, it will properly remove any decimal as intval does and remove any non-numeric characters.
<?php
function bigintval($value) {
$value = trim($value);
if (ctype_digit($value)) {
return $value;
}
$value = preg_replace("/[^0-9](.*)$/", '', $value);
if (ctype_digit($value)) {
return $value;
}
return 0;
}
// SOME TESTING
echo '"3147483647.37" : '.bigintval("3147483647.37")."<br />";
echo '"3498773982793749879873429874.30872974" : '.bigintval("3498773982793749879873429874.30872974")."<br />";
echo '"hi mom!" : '.bigintval("hi mom!")."<br />";
echo '"+0123.45e6" : '.bigintval("+0123.45e6")."<br />";
?>
Here is the produced output:
"3147483647.37" : 3147483647
"3498773982793749879873429874.30872974" : 3498773982793749879873429874
"hi mom!" : 0
"+0123.45e6" : 0
Hope that helps!
you can also use regular expressions to remove everything after the intial numeric parts:
<?php
$inputNumber = "3147483647.37";
$intNumber = preg_replace('/^([0-9]*).*$/', "\\1", $inputNumber);
echo $intNumber; // output: 3147483647
?>
Either use number_format($inputNumber, 0, '', '')
Or if you only want to check if its a whole number then use ctype_digit($inputNumber)
Don't use the proposed is_numeric, as also floats are numeric. e.g. "+0123.45e6" gets accepted by is_numeric
In addition to number_format, you can use sprintf:
sprintf("%.0f", 3147483647.37) // 3147483647
However, both solutions suffer from float overflow, for example:
sprintf("%.0f", 314734534534533454346483647.37) // 314734534534533440685998080
If you want to handle arbitrary-precision numbers, you will need to use the gmp extension. The function gmp_init(), for example, converts a string to a gmp resource object. the drawback is that you must use other functions of that extension to further process that object. Converting it back to a string is done using gmp_strval(), for example.
$gmpObject = gmp_init($string, 10);
if ($gmpObject === FALSE) {
# The string was not a valid number,
# handle this case here
}
echo gmp_strval($gmpObject);
You might want to only verify that the string is representing a valid number and use the string itself, if you do not intend to do any operations on the value. That can be done using a regular expression:
$containsInt = preg_match('/^\d+$/', $string);
# Or for floating point numbers:
$containsFloat = preg_match('/^\d+(.\d+)?$/', $string);
echo $string;
Another option is to use is_numeric(). But that function does more conversion than you might like. Quoting from docs of that function:
... +0123.45e6 is a valid numeric value ...
<?php
$a = 453453445435.4;
echo $bigint = floor($a);