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how to validate decimal numbers in PHP. I looked at is_numeric() but that won't work for me:
bool is_numeric ( mixed var )
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 +0123.45e6 is a valid numeric value. Hexadecimal notation (0xFF) is allowed too but only without sign, decimal and exponential part.
I don't want the exponent part or hexadecimal notation. The user will be entering in simple decimal values and I don't want a type-o that just happens to be a valid exponent or hex value to slip past. I'd just like "traditional" decimal numbers to be consdered valid.
EDIT here a simple (brute force) page that contains much more complete test data (what should and should not be considered a numeric value).
<html><head></head>
<body>
<?php
function TestFunction($s_value) {
//
// your code here
//
return; //true or false;
}
print '<b>these are valid numbers and should return "true"</b><br>';
print '<pre>';
$s_value='123'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='+1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='-1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value=' 1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1 '; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value=' 1 '; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='12345.1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='6789.01'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='-1.1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='+1.1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='0'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='00001.1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='.1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='.0000001';print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='5.'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
print '</pre>';
print '<br><b>these are NOT valid numbers and should return "false"</b><br>';
print '<pre>';
$s_value='--------------------------------';print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value=null; print "\n".'$s_value=null, TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='.'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value=''; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value=' '; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value=' '; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1abc'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='$1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1@'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1.2.1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='abc'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1.45e6'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='0xFF'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='++1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='--1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1+'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='1-'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='a1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='#1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='10.e5'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='0x1'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
$s_value='0x'; print "\n".'$s_value="'.$s_value.'", TestFunction()='.(TestFunction($s_value)?'true':'false');
print '</pre>';
?>
</body>
</html>
313
How do you check if number is decimal or not PHP? The is_numeric() function checks whether a variable is a number or a numeric string. This function returns true (1) if the variable is a number or a numeric string, otherwise it returns false/nothing.
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Updated with your test data.
function TestFunction($s_value) {
$regex = '/^\s*[+\-]?(?:\d+(?:\.\d*)?|\.\d+)\s*$/';
return preg_match($regex, $s_value);
}
$valid = TestFunction($input);
Or trim the input first
function TestFunction($s_value) {
$regex = '/^[+\-]?(?:\d+(?:\.\d*)?|\.\d+)$/';
return preg_match($regex, $s_value);
}
$input = trim($input);
$valid = TestFunction($input);
$decimal = preg_match('/^[+\-]?\d+(\.\d+)?$/', $value) ? (float)$value : 0.0;
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