❮ PHP Variable Handling Reference
Example
Return the float value of different variables:
Try it Yourself »
Definition and Usage
The floatval[] function returns the float value of a variable.
Syntax
Parameter Values
| variable | Required. Specifies the variable to check. Must be a scalar type |
Technical Details
| The float value of the variable on success, 0 on failure. An empty array will return 0, and a non-empty array will return 1 |
| Float |
| 4.2+ |
❮ PHP Variable Handling Reference
[PHP 4, PHP 5, PHP 7, PHP 8]
is_float — Finds whether the type of a variable is float
Description
is_float[mixed $value]: bool
Note:
To test if a variable is a number or a numeric string [such as form input, which is always a string], you must use is_numeric[].
Parameters
valueThe variable being evaluated.
Return Values
Returns
true if value is a float, false otherwise.
Examples
Example #1 is_float[] example
var_dump[is_float[27.25]];
var_dump[is_float['abc']];
var_dump[is_float[23]];
var_dump[is_float[23.5]];
var_dump[is_float[1e7]]; //Scientific Notation
var_dump[is_float[true]];
?>
The above example will output:
bool[true] bool[false] bool[false] bool[true] bool[true] bool[false]
See Also
- is_bool[] - Finds out whether a variable is a boolean
- is_int[] - Find whether the type of a variable is integer
- is_numeric[] - Finds whether a variable is a number or a numeric string
- is_string[] - Find whether the type of a variable is string
- is_array[] - Finds whether a variable is an array
- is_object[] - Finds whether a variable is an object
Anonymous ¶
1 year ago
is_float[] returns true for NAN, INF and -INF. You may want to test is_float[$value] && is_finite[$value], or alternatively filter_var[$value, FILTER_VALIDATE_FLOAT] !== false.
nonzer0value ¶
7 years ago
Coercing the value to float and back to string was a neat trick. You can also just add a literal 0 to whatever you're checking.
Seems to work ok:
YMMV
Boylett ¶
14 years ago
If you want to test whether a string is containing a float, rather than if a variable is a float, you can use this simple little function:
function isfloat[$f] return [$f == [string][float]$f];
Erutan409 at Hotmail dot com ¶
7 years ago
Boylett's solution is elegant [//php.net/manual/en/function.is-float.php#85848], but won't work for long float's or variables that are not explicitly type of 'string' or for long floats that are encased in quotes, making it a string that will be truncated/rounded when cast to a float. So, further logic must be completed to test for the case. Take the following example:
string[34] "3.14159265358979323846264338g32795"
Will produce [32-bit]:
float[3.1415926535898]
bool[false]
bool[false]
So far, so good, right? Yeah, but it's misleading, because the string is so long, that when it's converted to a float, it won't be equivalent to the comparison of the value being cast back into a string . So the aforementioned short function works. Look at this next example:
Will produce [32-bit]:
float[3.1415926535898]
float[3.1415926535898]
bool[false]
bool[true]
Why is it not working now, but the value is truly a float? Same reasoning as mentioned before. The float is so long that it's truncated/rounded and doesn't match the comparison being done with the short-hand function.
So, as you can see, more logic should be applied to the variable you're testing.
kshegunov at gmail dot com ¶
14 years ago
As celelibi at gmail dot com stated, is_float checks ONLY the type of the variable not the data it holds!
If you want to check if string represent a floating point value use the following regular expression and not is_float[],
or poorly written custom functions.
/^[+-]?[[[0-9]+]|[[0-9]*\.[0-9]+|[0-9]+\.[0-9]*]|
[[[0-9]+|[[0-9]*\.[0-9]+|[0-9]+\.[0-9]*]][eE][+-]?[0-9]+]]$/
KIVagant at gmail dot com ¶
10 years ago
Yet another regular expression for float in real life:
// Non-matches:
// Matches:
1, -1, 1.0, -1.0, '1', '-1', '1.0', '-1.0', '2.1', '0', 0, ' 0 ', ' 0.1 ', ' -0.0 ', -0.0, 3., '-3.', '.27', .27, '-0', '+4', '1e2', '+1353.0316547', '13213.032468e-13465', '-8E+3', '-1354.98879e+37436'
false, true, '', '-', '.a', '-1.a', '.a', '.', '-.', '1+', '1.3+', 'a1', 'e.e', '-e-4', 'e2', '8e', '3,25'
Mitch ¶
10 years ago
Another RegEx for matching floats:
/^[+-]?[\d*\.\d+[[eE]?[+-]?\d+]?|\d+[eE][+-]?\d+]$/
Matches:
1e2
+1353.0316547
13213.032468e-13465
-8E+3
-1354.98879e+37436
Non-matches:
8
e2
-e-4
E
asdf.safd
8e
Enjoy.
phper ¶
16 years ago
A better way to check for a certain number of decimal places is to use :
$num_dec_places = 2;
number_format[$value,$num_dec_places];
ivan dot maruca at gmail dot com ¶
6 years ago
check if string/numeric is float or not :
ckelley at the ca - cycleworks dot com ¶
14 years ago
Personally, I use an implicit cast:
if[ is_float[$value+1] ]{
$value=sprintf["%.2f",$value];
}
Which turns 22.0000000 query result into 22.00 for display to users.