Check for numbers in variable RESOLVED

What's the best way of checking that a variable only has numbers in it, so no letters or commas etc.

Use the is_numeric function.

PHP Code:

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<?php

$var1= "12three"; // alphanumeric
$var2 = "123"; // numeric string
$var3 = 123; // integer

if(is_numeric($var1))
{
    echo "this will not be echo'd because it is false";
}

if(is_numeric($var2))
{
    echo "this will be echo'd because it is true";
}

if(is_numeric($var3))
{
    echo "this will be echo'd because it is true";
}

?>

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If its from an imput form or something that's going to be a little but "less then perfect", you might want to do some cleanup to remove trailing spaces etc. (trim)

thnx for the reply, i'll give it a go.

It seems there's no need to do a Trim for an input form, bonus!!!

Thnx again.

careful as is_numeric will also detect this as numeric

4e4 and 444 // those are both correct.

you want this

Code:

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if (preg_match ("/^([0-9]+)$/", $input_number)) {
echo "true";
} else {
echo "false";
}

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