PHP determines whether it is a number

PHP is_numeric Detects whether a variable is a number or a numeric string (Recommended learning: PHP Programming from Beginner to Master)

bool is_numeric ( mixed $var )

Returns TRUE if var is a number or numeric string, otherwise returns FALSE.

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For example 1:

<?php
    $v = is_numeric (&#39;58635272821786587286382824657568871098287278276543219876543&#39;) ? true : false;
    
    var_dump ($v);
?>

The above script will output:

bool(true)

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For example 2:

<?php
$str="0";
$strTest=is_numeric(0);
var_dump($strTest);
?>
boolean true
//
function int_str($str){
    if(is_numeric($str)){
        $str = &#39;m&#39;.$str;
    }
    return $str;
}

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