I noticed PHP is_numeric() accepts "E" as a number.
I have a string: "88205052E00" and I want the result to be: NOT numeric.
Here is the code which I tested.
<?php
$notnumber = '88205052E00';
if(is_numeric($notnumber)) {
echo $notnumber . ' is a number';
} else {
echo $notnumber . ' is NOT a number';
}
?>
The Code above gives result:
88205052E00 is a number
How can I get the result to be: 88205052E00 is NOT a number?
I will keep the answer incase it helps but as pointed out there are shortcomings with ctype_digit in that it does not like - or ..
More likely then you want to use ctype_digit which checks if all of the characters in the provided string, text, are numerical.
Where as is_numeric — Finds whether a variable is a number or a numeric string
<?php
$s = "88205052E00";
if(ctype_digit($s)){
echo "Yes";
} else {
echo "No";
}
returns no.
3948394873281738173172493274871218201832081239183 to return true and false for -1.
E is valid because of floating point numbers (http://php.net/manual/en/language.types.float.php).
If you don't want to allow E for whatever reason, you could check for it independently:
if (strpos(strtolower($notnumber), 'e') === false && is_numeric($notnumber))
This makes sure that there isn't an E and that it is also numeric.
===, not !==Just use a regular expression:
<?php
if (preg_match("/^\-?[0-9]*\.?[0-9]+\z/", $notnumber)) {
echo "$notnumber is numeric\n";
} else {
echo "$notnumber is not numeric\n";
}
Results:
1234 is numeric
1234E56 is not numeric
-1234 is numeric
.1234 is numeric
-.1234 is numeric
-12.34 is numeric
Assuming you want to ensure that the string is a valid integer you could use filter_var:
$tests = ['1', '1.1', '1e0', '0x1'];
foreach($tests as $str) {
$int = filter_var($str, FILTER_VALIDATE_INT);
if ($int === false) {
echo $str . ' is not an integer' . PHP_EOL;
} else {
echo $str . ' is an integer' . PHP_EOL;
}
}
Result:
1 is an integer
1.1 is not an integer
1e0 is not an integer
0x1 is not an integer
is_int?is_int('1234') returns false.ctype_digit('239284923942734924729749327') is true but obviously it is too big for integer.Let's check the definition:
Finds whether the given variable is numeric. Numeric strings consist of optional sign, any number of digits, optional decimal part and optional exponential part. Thus
+0123.45e6is a valid numeric value. Hexadecimal (e.g.0xf4c3b00c) and binary (e.g.0b10100111001) notation is not allowed.
The relationship with floating point literals is clear but, how does it all relate to integer literals?
The manual doesn't state explicitly what the use cases are but in general it's more a helper tool (to ensure that you can feed stringified data to functions that expect numeric values) than a proper form validator. If input is collected in an environment where 88205052E00 is not expected then it might be a good idea to expect (and generate) localised data and implement a locale-aware solution.
Eis used in scientific notation, so yes, it is considered a valid number.0-9characters. And handles decimals.if you need them.