Decimal number regular expression, no any . {dot or point } Using PHP

Question

For example if I had:

Valid numbers would be 5 and 125.

Invalid numbers : 1.2, 1.65, 9.5

I am stuck in checking whether a number has a decimal or not.
I tried is_numeric but it accepted numbers with a decimal.

What? Could you clarify what you mean? Also please include a example and your expected output, also, have you tried something? — Epodax, Sep 15 '15 at 11:56
[ctype_digit](http://www.php.net/manual/en/function.ctype-digit.php) — Mark Baker, Sep 15 '15 at 11:57
*i want* Stack Overflow is not a free code writing service. Show us where you are stuck and we are happy to help — Rizier123, Sep 15 '15 at 11:58

score 1 · Answer 1 · edited May 23 '17 at 12:29

1

A possibility is to try using strpos:

if (strpos($a,'.') === false) { // or comma can be included as well
    echo 'Valid';
}

or try it using regex:

if (preg_match('/^\d+$/',$a))
    echo 'Valid';

Examples taken from here.

edited May 23 '17 at 12:29

Community

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answered Sep 15 '15 at 12:10

NeverHopeless

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`strpos()` won't work with an int, so you need to cast the ID to a string if you are gonna use `strpos()`. The variable might be a real int or float. – Timmetje Sep 15 '15 at 12:13
$a should be a string here. i have used `===` to compare types as well. – NeverHopeless Sep 15 '15 at 12:18
But we don't know if `$a` is a string, it could be anything. So you might want to add some code to make sure it is, or add checks if it's an integer or float. – Timmetje Sep 15 '15 at 12:20

Timmetje · Answer 2 · 2015-09-15T12:27:23.767

If you are sure the number variable is not a string you can use is_int() to check whether it is valid or is_float() to check whether it is invalid.

But if you handle forms for example the variable is often a string which makes it harder and this is an easy solution which works on strings, integers and floats:

if (is_numeric($number)) {
    //if we already know $number is numeric...
    if ((int) $number == $number) {
        //is an integer!!
    }
}

It's also faster than regex and string methods.

score 0 · Answer 3 · edited Sep 15 '15 at 12:38

0

Use is_float() function to find invalid numbers

edited Sep 15 '15 at 12:38

chris85

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answered Sep 15 '15 at 12:03

Samuel Kelemen

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Better to use `is_int` to find valid numbers :) – Timmetje Sep 15 '15 at 12:08

Decimal number regular expression, no any . {dot or point } Using PHP

3 Answers3