(PHP 4, PHP 5, PHP 7, PHP 8)
is_numeric — Finds whether a variable is a number or a numeric string
Determines if the given variable is a number or a numeric string.
valueThe variable being evaluated.
Returns true if value is a number or a
numeric string,
false otherwise.
| Version | Description |
|---|---|
| 8.0.0 |
Numeric strings ending with whitespace ("42 ") will now
return true. Previously, false was returned instead.
|
Example #1 is_numeric() examples
<?php
$tests = array(
"42",
1337,
0x539,
02471,
0b10100111001,
1337e0,
"0x539",
"02471",
"0b10100111001",
"1337e0",
"not numeric",
array(),
9.1,
null,
'',
);
foreach ($tests as $element) {
if (is_numeric($element)) {
echo var_export($element, true) . " is numeric", PHP_EOL;
} else {
echo var_export($element, true) . " is NOT numeric", PHP_EOL;
}
}
?>The above example will output:
'42' is numeric 1337 is numeric 1337 is numeric 1337 is numeric 1337 is numeric 1337.0 is numeric '0x539' is NOT numeric '02471' is numeric '0b10100111001' is NOT numeric '1337e0' is numeric 'not numeric' is NOT numeric array ( ) is NOT numeric 9.1 is numeric NULL is NOT numeric '' is NOT numeric
Example #2 is_numeric() with whitespace
<?php
$tests = [
" 42",
"42 ",
"\u{A0}9001", // non-breaking space
"9001\u{A0}", // non-breaking space
];
foreach ($tests as $element) {
if (is_numeric($element)) {
echo var_export($element, true) . " is numeric", PHP_EOL;
} else {
echo var_export($element, true) . " is NOT numeric", PHP_EOL;
}
}
?>Output of the above example in PHP 8:
' 42' is numeric '42 ' is numeric ' 9001' is NOT numeric '9001 ' is NOT numeric
Output of the above example in PHP 7:
' 42' is numeric '42 ' is NOT numeric ' 9001' is NOT numeric '9001 ' is NOT numeric