I have checked a bunch of posts on stackoverflow and on articles on google but none of them were able to answer my question. Here is my code (i've simplified it instead of posting my code)
$first = 10;
$second = 0; //comes from db row count
$total = !is_int($first/$second) ? 0 : $first/$second;
problem is when i do this I keep getting the Division by zero error. I have a bunch and $second isnt always 0, it can be any number. But it does come out to 0 since the row counts for whatever query it comes out as 0. Is there a safe way of checking to see if $first can be divided by $second without giving an error? I have tried # before the !is_int and that just breaks all other statements.
Try this:
$total = ($second == 0) ? 0 : $first / $second;
You can't divide by 0 it is undefined. If you want to handle division by 0 just check if the divisor isn't equals to 0. Or a safer way, chack if it is a positive integer:
$first = 10;
$dbRowCount = dbFunction();
if ($dbRowCount > 0) {
$total = $first / $dbRowCount;
} else {
//Error handling
}
The ternary structure can accept more than one condition. and it will work just as any other if condition, and won't try the second condition if the first fails.
So, just add it
$total = ($first!==0 && $second!==0 && !is_int($first/$second)) ? 0 : $first/$second;
You might want to try checking if your $Second variable is 0.
Something like:
$First = 10;
$Second = $row['table_column'];
if ($Second == 0) {
echo "Oops this will be an error";
}
else
$First/$second = $me;
I am trying to compare two values but when I do it does not appear to work. I know what the values are so it should be reporting true. Even worse, if I take either one of the variables out and put the number in it works.
$data = simplexml_load_file('xml/heroes/hero.xml')
or die("Error: Cannot create object");
$hme = $data->hes->he->maxen;
$hce = $data->hes->he->curen;
$hac = $data->hes->he->lastac;
echo $hce . ' should not be greater than ' . $hme;
if($hce > $hme){
echo 'should be working';
}
Outputs:
773 should not be greater than 20
I think your variable are like this
$hce = "773";
$hme = "20";
Before comparing them do intval
if(intval($hme)>intval($hce))
Cast your strings to integers:
$hme = (int)$data->hes->he->maxen;
$hce = (int)$data->hes->he->curen;
$hac = (int)$data->hes->he->lastac;
I think you took them as strings.I think you need to convert them to integer.
Simple function to do that:
int atoi(char *s)
{
int val = 0;
while (*s)
{
val *= 10;
val += (*s) - '0';
s++;
}
return val;
}
I'm very new to php. I have a json named json. When I try to do this:
echo $json->status;
I get :
CREATED
I try to compare this result with normal string CREATED like this:
if(strcasecmp("CREATED",$json->status))
{
print_r("Order created successfuly");
}
but for some reason the if condition is not evaluting to true. Even though I compare CREATED with CREATED!
Not sure where the error is.
Thanks in advance.
This function return zero if strings are equal
if (strcasecmp("CREATED",$json->status) == 0)
Look to the manual:
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
so strcasecmp('a','a') is 0, therefore you have to change your code into
if(strcasecmp("CREATED",$json->status) == 0)
{
print_r("Order created successfuly");
}
http://php.net/manual/en/function.strcasecmp.php
Quote from the page :
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
So strcasecmp('CREATED', 'CREATED') returns 0. And 0 is not equals to true.
You must do that :
if (strcasecmp("CREATED",$json->status) === 0) {
print_r("Order created successfuly");
}
if (strcasecmp( $json->status, "CREATED") == 0)
{
...
...
}
Why cant you just use a simpler if statement?
if( $json->status == "CREATED" ) {
print_r("Order created successfuly");
}
And check for whitespaces at the end or start of the status.
To compare strings, try to do the following :
if($json->status == "CREATED")
{
echo "Order created successfuly";
}
Trying to get a query string into a variable but only if it's an integer.
Code is probably a bit more complicated than it should be but this is where I'm up to-
//get page number. default is 1. check is not empty and is a number
if (empty($_GET['pag'])) {$page = 1;}
else if (is_int($_GET['pag'])){$page = $_GET['pag'];}
else {$page = 1;}
Where am I going wrong?
You probably want is_numeric() instead - is_int() doesn't test to see if a string is a numeric string.
if (empty($_GET['pag'])) {$page = 1;}
else if (is_numeric($_GET['pag'])){$page = (int) $_GET['pag'];}
else {$page = 1;}
I would suggest, type cast the value to an integer:
$page = empty($_GET['pag']) ? 1 : (int) $_GET['pag'];
Although, if I remember well, type casting something that is not an integer will make it a 0, but you should check anyways if the $page is in between bounds before doing anything with it, because the user might as well type in ?pag0 in your URL.
$page = ((isset($_GET['pag']) && is_numeric($_GET['pag'])) ? (int)$_GET['pag'] : 1;
I need to check for a form input value to be a positive integer (not just an integer), and I noticed another snippet using the code below:
$i = $user_input_value;
if (!is_numeric($i) || $i < 1 || $i != round($i)) {
return TRUE;
}
I was wondering if there's any advantage to using the three checks above, instead of just doing something like so:
$i = $user_input_value;
if (!is_int($i) && $i < 1) {
return TRUE;
}
Not sure why there's no suggestion to use filter_var on this. I know it's an old thread, but maybe it will help someone out (after all, I ended up here, right?).
$filter_options = array(
'options' => array( 'min_range' => 0)
);
if( filter_var( $i, FILTER_VALIDATE_INT, $filter_options ) !== FALSE) {
...
}
You could also add a maximum value as well.
$filter_options = array(
'options' => array( 'min_range' => 0,
'max_range' => 100 )
);
Learn more about filters.
the difference between your two code snippets is that is_numeric($i) also returns true if $i is a numeric string, but is_int($i) only returns true if $i is an integer and not if $i is an integer string. That is why you should use the first code snippet if you also want to return true if $i is an integer string (e.g. if $i == "19" and not $i == 19).
See these references for more information:
php is_numeric function
php is_int function
The best way for checking for positive integers when the variable can be INTEGER or STRING representing the integer:
if ((is_int($value) || ctype_digit($value)) && (int)$value > 0 ) { // int }
is_int() will return true if the value type is integer. ctype_digit() will return true if the type is string but the value of the string is an integer.
The difference between this check and is_numeric() is that is_numeric() will return true even for the values that represent numbers that are not integers (e.g. "+0.123").
It's definitely heading towards the land of micro-optimisation, but hey: the code I'm working on chews through millions of items every day and it's Friday. So I did a little bit of experimenting...
for ($i = 0; $i < 1000000; $i++) {
// Option 1: simple casting/equivalence testing
if ((int) $value == $value && $value > 0) { ... }
// Option 2: using is_int() and ctype_digit(). Note that ctype_digit implicitly rejects negative values!
if ((is_int($value) && $value > 0) || ctype_digit($value)) { ... }
// Option 3: regular expressions
if (preg_match('/^\d+$/', $value)) { ... }
}
I then ran the above tests for both integer and string values
Option 1: simple casting/equivalence testing
Integer: 0.3s
String: 0.4s
Option 2: using is_int() and ctype_digit()
Integer: 0.9s
String: 1.45s
Option 3: regular expressions
Integer: 1.83s
String: 1.60s
Perhaps unsurprisingly, option 1 is by far the quickest, since there's no function calls, just casting. It's also worth noting that unlike the other methods, option 1 treats the string-float-integer value "5.0" as an integer:
$valList = array(5, '5', '5.0', -5, '-5', 'fred');
foreach ($valList as $value) {
if ((int) $value == $value && $value > 0) {
print "Yes: " . var_export($value, true) . " is a positive integer\n";
} else {
print "No: " . var_export($value, true) . " is not a positive integer\n";
}
}
Yes: 5 is a positive integer
Yes: '5' is a positive integer
Yes: '5.0' is a positive integer
No: -5 is not a positive integer
No: '-5' is not a positive integer
No: 'fred' is not a positive integer
Whether or not that's a good thing for your particular use-case is left as an exercise for the reader...
The other best way to check a Integer number is using regular expression. You can use the following code to check Integer value. It will false for float values.
if(preg_match('/^\d+$/',$i)) {
// valid input.
} else {
// invalid input.
}
It's better if you can check whether $i > 0 too.
preg_match('{^[0-9]*$}',$string))
and if you want to limit the length:
preg_match('{^[0-9]{1,3}$}',$string)) //minimum of 1 max of 3
So pisitive int with a max length of 6:
if(preg_match('{^[0-9]{1,6}$}',$string)) && $string >= 0)
You don't really need to use all three check and if you want a positive integer you might want to do the opposite of what is in your code:
if(is_numeric($i) && $i >= 0) { return true; }
Check Sören's answer for more information concerning the difference between is_int() and is_numeric()
if(preg_match('/^[1-9]\d*$/',$i)) {
//Positive and > 0
}
Rather than checking for int OR string with multiple conditions like:
if ( ctype_digit($i) || ( is_int($i) && $i > 0 ) )
{
return TRUE;
}
you can simplify this by just casting the input to (string) so that the one ctype_digit call will check both string and int inputs:
if( ctype_digit( (string)$i ) )
{
return TRUE;
}
In addition to all the other answers: You are probably looking for ctype_digit. It looks for a string containing only digits.
Definition:
!A = !is_numeric($i)
B = $i < 1
!C = $i != round($i)
Then...
!is_numeric($i) || $i < 1 || $i != round($i) is equal to
!A || B || !C
So:
!A || B || !C = !A || !C || B
Now, using the deMorgan theorem, i.e. (!A || !C) = (A && C), then:
!A || !C || B = (A && C) || B
Now, note that A && C = is_numeric($i) && $i == round($i), but if $i == round($i) is TRUE, then is_numeric($i) is TRUE as well, so we can simplify A && C = C so,
(A && C) || B = C || B =
$i == round($i) || $i < 1
So you just need to use:
$i = $user_input_value;
if ($i == round($i) || $i < 1) {
return TRUE;
}
Laravel 4.2 Validation rule for positive number
It takes only positive numbers including float values.
public static $rules = array(
'field_name' => 'required|regex:/^\d*\.?\d*$/'
);
e.g:20,2.6,06
The first example is using round to verify that the input is an integer, and not a different numeric value (ie: a decimal).
is_int will return false if passed a string. See the PHP manual examples for is_int
To check for positive integer use:
$i = $user_input_value;
if (is_int($i) && $i > 0) {
return true; //or any other instructions
}
OR
$i = $user_input_value;
if (!is_int($i) || $i < 1) {
return false; //or any other instructions
}
Use the one that fits your purpose as they are the same. The following examples demonstrate the difference between is_numeric() and is_int():
is_numeric(0); // returns true
is_numeric(7); // returns true
is_numeric(-7); // returns true
is_numeric(7.2); // returns true
is_numeric("7"); // returns true
is_numeric("-7"); // returns true
is_numeric("7.2"); // returns true
is_numeric("abc"); // returns false
is_int(0); // returns true
is_int(7); // returns true
is_int(-7); // returns true
is_int(7.2); // returns false
is_int("7"); // returns false
is_int("-7"); // returns false
is_int("7.2"); // returns false
is_int("abc"); // returns false
All these answers overlook the fact that the requestor may checking form input.
The is_int() will fail because the form input is a string.
is_numeric() will be true also for float numbers.
That is why the $i == round($i) comes in as it checks for the input being a whole number.
Ok, I know this thread is really old but I share #Jeffrey Vdovjak's opinion: since I was able to find it, it might still help someone else out there.
php's gmp_sign() might be another easy way to check. It works for integer and numeric strings, and returns 1 if a is positive, -1 if a is negative, and 0 if a is zero.
So:
// positive
echo gmp_sign("500") . "\n";
// negative
echo gmp_sign("-500") . "\n";
// zero
echo gmp_sign("0") . "\n";
will output:
1
-1
0
See function manual at http://php.net/manual/en/function.gmp-sign.php
P.S. You'll need to have php_gmp.dll enabled in your .ini file.
This's my solution, hope helpful :
if (is_numeric($i) && (intval($i) == floatval($i)) && intval($i) > 0)
echo "positive integer";
i check if string is numeric, second check to sure it's integer and third to sure it positive
If you use "is_int" the variable must be integer, so it can't be a float value. (no round needed).
if(isset($i) && is_int($i) && $i >= 0){ //0 is technically a postive integer I suppose
return TRUE; //or FALSE I think in your case.
}
I would do something like this:
if ((int) $i > 0) {
// this number is positive
}
The number gets typecast to a positive or negative number depending on the minus sign being at the front. Then compares the typecast number to being greater than 0 to determine if the number is positive.